First‐Principles Studies on the Atomistic Properties of Metallic Magnesium as Anode Material in Magnesium‐Ion Batteries

Rechargeable magnesium-ion batteries (MIBs) are a promising alternative to commercial lithium-ion batteries (LIBs). They are safer to handle, environmentally more friendly, and provide a five-time higher volumetric capacity (3832 mAh cm$^{-3}$) than commercialized LIBs. However, the formation of a passivation layer on metallic Mg electrodes is still a major challenge towards their commercialization. Using density functional theory (DFT), the atomistic properties of metallic magnesium, mainly well-selected self-diffusion processes on perfect and imperfect Mg surfaces were investigated to better understand the initial surface growth phenomena. Subsequently, rate constants and activation temperatures of crucial diffusion processes on Mg(0001) and Mg(10$_{\overline{1}}$ 1) were determined, providing preliminary insights into the surface kinetics of metallic Mg electrodes. The obtained DFT results provide a data set for parametrizing a force field for metallic Mg or performing kinetic Monte-Carlo simulations

Development of a Mg/O ReaxFF Potential to describe the Passivation Processes in Magnesium‐Ion Batteries

One of the key challenges preventing the breakthrough of magnesium-ion batteries (MIB) is the formation of a passivating boundary layer at the Mg anode. To describe the initial steps of Mg anode degradation by O$_2$ impurities, a Mg/O ReaxFF (force field for reactive systems) parameter set was developed capable of accurately modeling the bulk, surface, adsorption, and diffusion properties of metallic Mg and the salt MgO. It is shown that O$_2$ immediately dissociates upon first contact with the Mg anode (modeled as Mg(0001), Mg(10$\bar1$0)A, and Mg(10$\bar1$1)), heating the surface to several 1000 K. The high temperature assists the further oxidation and forms a rock salt interphase intersected by several grain boundaries. Among the Mg surface terminations, Mg(10$\bar1$0)A is the most reactive, forming an MgO layer with a thickness of up to 25 Å. The trained force field can be used to model the ongoing reactions in Mg–air batteries but also to study the oxidation of magnesium metal in general

Suitability of Carbazolyl Hauser and Turbo‐Hauser Bases as Magnesium‐Based Electrolytes

Lithium-ion batteries pose certain drawbacks and alternatives are highly demanded. Requirements such as low corrosiveness, electrochemical stability and suitable electrolytes can be met by magnesium-ion batteries. Metalation of carbazole with Mg in THF in the presence of ethyl bromide yields the sparingly soluble Hauser base [(thf)$_{3}$Mg(Carb)Br] (1) which shows a Schlenk-type equilibrium with formation of [(thf)$_{3}$Mg(Carb)$_{2}$] and [(thf)4MgBr2]. A THF solution of 1 shows a low over-potential and a good cyclability of electrodeposition/-stripping of Mg on a Cu current collector. An improved performance is achieved with the turbo-Hauser bases [(thf)(Carb)Mg(μ-Br/X)$_{2}$Li(thf)$_{2}$] (X=Br (2) and Cl (3)) which show a significantly higher solubility in ethereal solvents. The THF solvation energies increase from (thf)$_{x}$MgBr$_{2}$ over (thf)$_{x}$Mg(Carb)Br to (thf)$_{x}$Mg(Carb)$_{2}$ for an equal number x of ligated THF molecules

C like clever and cycle : without a smart and systematic conception of the metal industry, product labelling and an indicator system, nothing will happen

The earth's capacity to absorb greenhouse gases is ultimately a critical limiting factor in the handling of metals. The fact that the demand for metals far exceeds their secondary production is extremely problematic at this point. Nevertheless, metals are crucial for climate protection and energy system transformation. Examples are the rare earth metal neodymium used in high-performance permanent magnets in wind turbines, the alkali metal lithium as the most important component in batteries, or the metal tellurium used in thin-film solar cells to generate solar power. It is therefore essential to promote the aspects of resource efficiency and to strengthen the critical role of metals in national and European policy programs. Next to a global solution, a European solo effort with predominantly market-based instruments and the effects of committed behaviour by civil society in the European Union (EU), show that the EU can make a considerable contribution to sustainable development on its own. Thus, a comprehensive approach is needed for sustainable metal management in the sense of a circular economy on the European level fostering sustainable production and consumption pathways. But, this need and the special role of metals are not seen in the current debate about resources in society and politics. Due to the fact that in public perception, metallic raw materials are often discussed as less urgent than energy or polymer raw materials, this article aims to highlight the critical role of metals. Further, the objective of this contribution is to show which prerequisites exist for the development and establishment of a holistic metal management and where political strategies have to start. Challenges needed to be overcome to achieve such a holistic metal strategy and management are highlighted. In particular, the role of the metal industry, circular product design and labelling and corresponding indicator systems is examined. In addition, the special role of digitalisation is being worked out. Finally, conclusions are drawn and shown which aspects have to be considered for a holistic metal strategy and management

Conservation of the textile heritage in Alsace between materiality, immateriality, virtuality : what issues ? what paths ?

L'Alsace a été profondément marquée par l'industrie textile. Depuis près de deux siècles, cet héritage se compose, se transmet puis se démantèle avec les taux de croissance structurels et conjoncturels de l'économie et les crises industrielles. Puis, il se recompose de manières arbitraire, hasardeuse, voire opportune (au-delà de la rationalité plus ou moins assurée de stratégie(s) à court terme), pour former de ce fait un paysage culturel, scientifique, technique et industriel unique à chaque instant. Il est alors tout à fait légitime de se demander comment mettre en mémoire l'évolution de ce tissu industriel ans toute sa complexité ? Trois modes de conservation sont potentiellement exploitables : matérielle (concept de la rétro-présence à la néo-présence), immatérielle (concept de mémo-rétroconstruction) et virtuelle (concept d'aréel, favorisant clairement la prise de position sur des contenus matériels e immatériels à sauvegarder). Même si toutes ces possibilités coexistent, un problème reste entier : quelle trajectoire se dessine pour la conservation du patrimoine de l'industrie textile en Alsace ? La littérature sur la conservation du patrimoine industriel existante depuis les années 1970 tend à délaisser les relations d'interdépendances existantes entre ces trois modes de conservation. Le peu de résultats disponibles ne permet pas d'apprécier ce que pourrait nous apporter une bonne gestion de ces trois modes de conservation combinés. Ce travail de recherche s'est donné comme objectif de proposer des schémas possibles pour définir un nouveau modèle de conservation, basé sur l'exemple du patrimoine industriel textile en Alsace. La première partie de cette étude explique les processus qui ont permis le passage de l'industrie textile en Alsace au statut de patrimoine. Des choix guidés par des pouvoirs discrétionnaires, des logiques de conservation opposables, une discontinuité de ligne de conduite sur des courtes et longues périodes, de réoccupations parfois plus électoralistes que scientifiques, des désengagements d'hommes de responsabilités ou encore le manque de cohérence entre les acteurs ou les institutions... ont orienté la stratégie de la politique de conservation d'une région. Quel état des lieux peut-on dresser aujourd'hui grâce aux sources historiques ? Quels enjeux se profilent à court, moyen et long terme ? La seconde partie pose les mêmes questions, mais cette fois-ci en recherchant les réponses par l'exploitation exclusive de sources médiatiques. Elle interroge la pertinence des processus actuels de conservation du patrimoine de l'industrie textile, qu'ils soient matériel, immatériel ou virtuel avec un regard complémentaire à la première partie de cette étude, celui des journalistes, de la représentation publique et politique. Les sciences de l'information et de la communication apportent-elles de nouveaux horizons à la conservation de patrimoine ? Oui, mais pas seulement. Elles ne se limitent pas au rôle d'outils, mais nous verrons comment elles ont un rôle déterminant dans la reconstruction un patrimoine : elles se mettent collectivement en mouvement avec la société pour la définir, en exploitant tous les sens accumulés dans les sèmes liés au patrimoine industriel textile. Elles reconstituent ainsi une référence collective et formulent des hypothèses de transformation, d'adaptation et de projections futures. Nous verrons alors s'il est envisageable de leur réserver un rôle dans la conservation du patrimoine.La troisième partie met en évidence des convergences et les divergences des trois modes de conservation. Elle propose des solutions concrètes pour l'Alsace, puis des concepts transposables pour ouvrir ce nouveaux processus de conservation vers d'autres régions françaises ou pourquoi pas vers d'autre thématiques.Alsace has been profoundly marked by the textile industry. For two centuries, its textile heritage has experienced numerous fluctuations, rising and falling according to the structural and cyclical growth rate of the economy and to industrial crises. Fluctuations that, though completely random and uncontrollable (strategies, even short-term, cannot be implemented), have occurred in a timely manner, thus giving rise to constantly changing unique cultural, scientific, technical and industrial landscape.It is thus only right to wonder how the memory of the development of this industrial fabric can be preserved in all its complexity? There are three possible means of preservation: material (retro-presence to neo presence concept), immaterial (concept of memo-retroconstruction) and virtual (concept of what is "areal", clearly promoting position take-up on material and immaterial concepts to be protected). Even if all these possibilities exist side by side, one problem remains unanswered, namely what is the outlook for the preservation of the textile heritage in Alsace? The literature on preservation of industrial heritage available since the 1970s tends to overlook the existing relationships of interdependence between these three modes of preservation. The shortage of results does not allow us to appraise the potential offered by proper management of a combination of these three modes of preservation. This research work thus aims to propose some possible schemes to define a new preservation model, based on the example of the textile industrial heritage in Alsace. The first part of this study explains the processes that have allowed the textile industry in Alsace to accede to heritage status some 200 years ago. Choices guided by discretionary powers, opposable preservation logics, discontinuity in course of action over short and long periods alike, reclaiming more often oriented by lections rather than of a scientific nature, opting-out of those with responsibilities, not to mention the lack of coherence between players and institutions: these are all factors that will guide a Region's preservation policy strategy. What state of affairs can be drawn up today by historical sources? What is the outlook for the future? The second part asks the same questions, but this time seeks for the answers based only on media sources. It questions the pertinence of the current textile heritage preservation processes, material, immaterial and virtual alike, but from a viewpoint different from and complementary to the first part, namely the viewpoint of journalists and public and political contributors. Do communication sciences offer heritage reservation new horizons? Yes they do, but that is not all they offer. We shall see that, far from being mere tool, they play a decisive role in the reconstruction of a heritage, grouping themselves to move with society in order to define it by using all the meanings accumulated in the semes relating to the textile industrial heritage. Through this they form a collective reference, formulating hypotheses for future transformation, adaptation and projections. We shall then see whether it is possible for them to play a role in heritage preservation.The third part highlights the convergences and divergences of the three preservation modes. lt suggest concrete solutions for Alsace, followed by transposable concepts to extend these new preservation processes to other regions in France and, why not, to other areas

Biogas Processing - Final Report

Anaerobic digestion offers an effective way to manage dairy manure by addressing the principal problem of odor and environmental control while offering an opportunity to create energy from the conversion of biogas with a system of combined heat and power (CHP). The use of biogas as an energy source has numerous applications. However, all of the possible applications require knowledge about the composition and quantity of constituents in the biogas stream. This study provides data on the composition of anaerobic digestion biogas (ADG) over time (hourly, daily, weekly and year), results from the use of dairy-manure compost as a biofilter to remove hydrogen sulfide H2S from the ADG, and an assessment of the feasibility of injecting ADG into the natural gas pipeline. Results agree well with the often quoted generalized concentrations of 60% CH4, 40% CO2 and 600 BTUs for dairy-derived biogas. They also show that, depending on additives to the dairy manure and quality of farm water supply, the H2S concentrations can vary substantially from less than 1000 ppm to well over 6000 ppm. Utilization of cow-manure compost for removal of H2S from AD biogas using small-scale reactors was studied and shows promise. A technical and economic assessment of processing of biogas for injection to the natural gas pipeline, while dependent on biogas quantity, price for processed biogas, proximity of the biogas producer to the natural gas pipeline and the interest rate, suggests that a real possibility exists for injecting biogas to the natural gas pipeline dependent, of course, on the values of the parameters indicated

Petrology of the Quaternary volcanic centers in the Quesnel Highlands and Garibaldi Provincial Park areas, British Columbia

Bibliography: p. 127-132

First-principles studies on the atomistic properties of metallic magnesium as anode material in magnesium-based batteries

Rechargeable magnesium-ion batteries (MIBs) are a promising alternative to commercial lithium-ion batteries (LIBs). They are safer to handle, environmentally more friendly, and provide a five-time higher volumetric capacity (3832 mAh·cm-3) than commercialized LIBs. However, the formation of a passivation layer on metallic Mg electrodes is still a major challenge towards their commercialization. Using density functional theory, the atomistic properties of metallic magnesium, such as bulk, surface, and adsorption properties, were examined. Well-selected self-diffusion processes on perfect and imperfect Mg surfaces were investigated to better understand the initial surface growth phenomena. Subsequently, rate constants and activation temperatures of crucial diffusion processes on Mg(0001) and Mg(101m1) were determined, providing preliminary insights into the surface kinetics of metallic Mg electrodes