Bioboden - gut fürs Klima

Wie klimawirksam ist welche Art der Bodenbewirtschaftung? Und wie viel Humus entsteht dabei? Wissenschaftler beschäftigen sich immer wieder mit diesem Thema. Minou Menzler befragte hierzu den Bodenexperten Andreas Gattinger

Noninvasive optical inhibition with a red-shifted microbial rhodopsin

Optogenetic inhibition of the electrical activity of neurons enables the causal assessment of their contributions to brain functions. Red light penetrates deeper into tissue than other visible wavelengths. We present a red-shifted cruxhalorhodopsin, Jaws, derived from Haloarcula (Halobacterium) salinarum (strain Shark) and engineered to result in red light–induced photocurrents three times those of earlier silencers. Jaws exhibits robust inhibition of sensory-evoked neural activity in the cortex and results in strong light responses when used in retinas of retinitis pigmentosa model mice. We also demonstrate that Jaws can noninvasively mediate transcranial optical inhibition of neurons deep in the brains of awake mice. The noninvasive optogenetic inhibition opened up by Jaws enables a variety of important neuroscience experiments and offers a powerful general-use chloride pump for basic and applied neuroscience.McGovern Institute for Brain Research at MIT (Razin Fellowship)United States. Defense Advanced Research Projects Agency. Living Foundries Program (HR0011-12-C-0068)Harvard-MIT Joint Research Grants Program in Basic NeuroscienceHuman Frontier Science Program (Strasbourg, France)Institution of Engineering and Technology (A. F. Harvey Prize)McGovern Institute for Brain Research at MIT. Neurotechnology (MINT) ProgramNew York Stem Cell Foundation (Robertson Investigator Award)National Institutes of Health (U.S.) (New Innovator Award 1DP2OD002002)National Institute of General Medical Sciences (U.S.) (EUREKA Award 1R01NS075421)National Institutes of Health (U.S.) (Grant 1R01DA029639)National Institutes of Health (U.S.) (Grant 1RC1MH088182)National Institutes of Health (U.S.) (Grant 1R01NS067199)National Science Foundation (U.S.) (Career Award CBET 1053233)National Science Foundation (U.S.) (Grant EFRI0835878)National Science Foundation (U.S.) (Grant DMS0848804)Society for Neuroscience (Research Award for Innovation in Neuroscience)Wallace H. Coulter FoundationNational Institutes of Health (U.S.) (RO1 MH091220-01)Whitehall FoundationEsther A. & Joseph Klingenstein Fund, Inc.JPB FoundationPIIF FundingNational Institute of Mental Health (U.S.) (R01-MH102441-01)National Institutes of Health (U.S.) (DP2-OD-017366-01)Massachusetts Institute of Technology. Simons Center for the Social Brai

Reversible oxygen-ion storage for solid oxide cells

In a rechargeable oxide battery (ROB) a solid oxide cell (SOC) is combined with an integrated iron oxide base storage for oxygen ions. The cell is operated at 800°C alternately as fuel cell and as electrolyser and the storage material regulates the oxygen partial pressure at the fuel electrode in a range of approximately 10-21-10-18 bar. Repeated charging (electrolysis) and discharging (fuel cell mode) can lead to a degradation of the storage material (particle coarsening, layer formation). In this study the influence of additions of Al2O3, CeO2, Mn3O4, Cr2O3, TiO2, SiO2, and MgO to the Fe2O3 base on these detrimental effects is analysed. Hence, compacted samples are repeatedly oxidised and reduced in a laboratory furnace, where the conditions present in the ROB are simulated. Using XRD and laser microscopy it was found that among the tested oxides only MgO and Al2O3 could mitigate the degradation phenomena to some extent.</jats:p

Recycling possibilities and strategies for solid oxide cell stacks

The decision of the European Union to make Europe the first carbon dioxide-neutral continent on earth pushes environmental-friendly technologies in all technical areas drastically forward. Thus, for the energy sector the conversion of kinetic energy into electricity must be ensured by non CO2-emitting techniques like wind and solar power (so called regenerative sources). As both are depending on natural limitations (wind blowing, sun shining) electricity storage becomes the dominant pre-requisite for such a regenerative-based energy future. Therefore, electrolyzers (low- and high-temperature) will be established in the future to a large extent. As SOECs are typically based on classical SOFC technology they are easily available and capable of being integrated. One additional aspect to the carbon-neutral future is that all technologies must also be striven forward with respect to refurbishing, reuse or recycling (Fig. 1). Within the “Energiewende” the German government has proclaimed the goal of “green hydrogen” as basis of its use as direct fuel or first link to an e-fuel or chemical development chain. In this context, a BMBF-funded technology platform H2Giga was founded with the aim of establishing the existing electrolyzer technologies on an industrial scale. Part of the technology platform is a recycling-related project called ReNaRe aiming for recycling possibilities and strategies for electrolyzers. The own research will focus on the first steps within the project dealing with recycling and reuse of either the metallic parts or the ceramic parts of an SOEC stack. The required stack or stack parts are delivered by Hexis and Jülich and hopefully also from Sunfire (being part of H2Giga) and characterized with respect to recycling possibilities, ways and technologies. First recycling ideas related to different SOC designs will be presented

Performance assessment of industrial-sized solid oxide cells operated in a reversible mode: Detailed numerical and experimental study

Reversible solid oxide cells (rSOCs) present a unique possibility in comparison to other available technologies to generate electricity, heat and valuable fuels in one system, in a highly-efficient manner. The major issue hindering their commercialization are system reliability and durability. A detailed understanding of the processes and mechanisms that occur within rSOCs of industrial-size, is of critical importance for addressing this challenge. This study provides in-depth insight into behavior of large planar rSOCs based on a comprehensive experimental and numerical study. All the numerical data obtained are validated with the in-house made cells and experiments. The sensitivity analysis, which covers a wide range of operating conditions relevant for industrial-sized systems, such as varying operating temperature, H2/H2O-ratio, operating current etc., provides very good accordance of the cell performance measured and simulated. It reveals that lowering fuel volume and thus causing fuel starvation has more pronounced effect in an electrolysis mode, which is visible in both the low-frequency and the middle-frequency range. Moreover, both co- and counter-flow are appropriate for the reversible operation. However, more uniform current density distribution is achievable for the counter-flow, which is of crucial importance for the real system design. The most accurate performance prediction can be achieved when dividing the cell into 15 segments. Slightly lower accuracy is reached by logarithmic averaging the fuel compositions, thus reducing the calculation time required. A computationally- and time-efficient model with very precise performance prediction for industrial-sized cells is thus developed and validated