Future recycling flows of tellurium from cadmium telluride photovoltaic waste

According to the European Photovoltaic Industry Association, photovoltaic energy has the potential to contribute up to 13% to the global electricity supply by 2040. A part of this electricity production will come from thin-film photovoltaic technologies. From various thin-film technologies available on the market today, low-cost cadmium telluride photovoltaics (CdTe-PV) can be considered the market leader with a market share of 5% at annual production. There are however two major concerns about this technology: first, the potential negative environmental impacts of cadmium contamination from CdTe-PV; and second, the possible shortage of the metal tellurium in the future. Because of these concerns, the recycling of production scrap and end-of-life PV modules is essential. In this paper we estimate how much tellurium will be recovered from PV scrap to substitute for primary tellurium. In order to estimate global tellurium flows until 2040, we have created a dynamic material flow model for the life-cycle of CdTe-PV modules. Three scenarios, which describe different market developments and technology trajectories, show how material efficiency measures – higher material utilization in production, decrease of material content in PV modules, and recycling of production scrap and end-of-life modules – will affect demand, waste flows, and recycling flows of semiconductor grade tellurium. The results depict that efficiency measures at process and cell level will reduce the specific tellurium demand per watt peak such that total tellurium demand starts to decline after 2020 despite further market growth. Thus, the CdTe-PV industry has the potential to fully rely on tellurium from recycled end-of-life modules by 2038. However, in order to achieve this goal, material efficiency must be substantially improved and efficient collection and recycling systems have to be built up

Dauerndes Lernziel: bewusst konsumieren!; Verknappung der Ressourcen erfordert neuen Lebensstil

Der gemäßigte oder ungebremste Konsum und die Diversifizierung von Lebensstilen können im Hinblick auf den aktuellen Ressourcen- und Energieverbrauch zum Problem werden, das voraussichtlich in den nächsten Jahren massive Folgen in den unterschiedlichsten Dimensionen haben wird: eine Herausforderung für die Erwachsenenbildung

Thermochemical Reactivity of Metal Carbonates

The thermochemical reactivity of alkaline earth metal and transition-metal carbonates is discussed. Emphasis is given to the dependence of degradation mechanisms and the concomitant formation of solid and volatile products on temperature range, gas atmosphere, and type of energy impact. The experimental findings comprise informative aspects, how immobilized inorganic carbon, i.e. as metal carbonate, can be converted by heterogeneous solid-state decompositions and/or in situ catalysis into inorganic solid products and into volatile organic carbon compounds

Evidence for a Ru4+^{4+} Kondo Lattice in LaCu3_3Ru4_4O12_{12}

Rare $d$-electron derived heavy-fermion properties of the solid-solution series LaCu$_3$Ru$_x$Ti$_{4-x}$O$_{12}$ were studied for $1 \leq x \leq 4$ by resistivity, susceptibility, specific-heat measurements, and magnetic-resonance techniques. The pure ruthenate ($x = 4$) is a heavy-fermion metal characterized by a resistivity proportional to $T^2$ at low temperatures $T$. The coherent Kondo lattice formed by the localized Ru 4$d$ electrons is screened by the conduction electrons leading to strongly enhanced effective electron masses. By increasing titanium substitution the Kondo lattice becomes diluted resulting in single-ion Kondo properties like in the paradigm $4f$-based heavy-fermion compound Ce$_x$La$_{1-x}$Cu$_{2.05}$Si$_2$ [M. Ocko {\em et al.}, Phys. Rev. B \textbf{64}, 195106 (2001)]. In LaCu$_3$Ru$_x$Ti$_{4-x}$O$_{12}$ the heavy-fermion behavior finally breaks down on crossing the metal-to-insulator transition close to $x = 2$.Comment: 9 pages, 8 figure

Intake of silica nanoparticles by giant lipid vesicles: influence of particle size and thermodynamic membrane state

The uptake of nanoparticles into cells often involves their engulfment by the plasma membrane and a fission of the latter. Understanding the physical mechanisms underlying these uptake processes may be achieved by the investigation of simple model systems that can be compared to theoretical models. Here, we present experiments on a massive uptake of silica nanoparticles by giant unilamellar lipid vesicles (GUVs). We find that this uptake process depends on the size of the particles as well as on the thermodynamic state of the lipid membrane. Our findings are discussed in the light of several theoretical models and indicate that these models have to be extended in order to capture the interaction between nanomaterials and biological membranes correctly

Intake of silica nanoparticles by giant lipid vesicles: influence of particle size and thermodynamic membrane state

The uptake of nanoparticles into cells often involves their engulfment by the plasma membrane and a fission of the latter. Understanding the physical mechanisms underlying these uptake processes may be achieved by the investigation of simple model systems that can be compared to theoretical models. Here, we present experiments on a massive uptake of silica nanoparticles by giant unilamellar lipid vesicles (GUVs). We find that this uptake process depends on the size of the particles as well as on the thermodynamic state of the lipid membrane. Our findings are discussed in the light of several theoretical models and indicate that these models have to be extended in order to capture the interaction between nanomaterials and biological membranes correctly