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- ItemIon dynamics in Al-Stabilized Li7La3Zr2O12 single crystals – Macroscopic transport and the elementary steps of ion hopping(Amsterdam : Elsevier, 2020) Posch, Patrick; Lunghammer, Sarah; Berendts, Stefan; Ganschow, Steffen; Redhammer, Günther J.; Wilkening, Alexandra; Lerch, Martin; Gadermaier, Bernhard; Rettenwander, Daniel; Wilkening, H. Martin R.Li7La3Zr2O12 (LLZO) garnet-type ceramics are considered as very promising candidates for solid electrolytes and have been extensively studied in the past few years. Several studies report on an increase in ionic conductivity by doping with ions, such as Al3+ and Ga3+, to stabilize the cubic modification of LLZO. Unfortunately, so far ion dynamics have mainly been studied using powdered samples. Such studies may suffer from chemical heterogeneities concerning Al distribution. Here, we took advantage of Al-stabilized LLZO single crystals to throw light on the elementary steps of ion hopping. We used 7Li nuclear magnetic resonance (NMR) spin-lattice relaxation measurements and conductivity spectroscopy to probe dynamic parameters from both a microscopic and macroscopic point of view. At 293 K the total conductivity turned out to be 0.082 mS cm−1, which is remarkably good for LLZO exhibiting an Al-content of only 0.37 wt%. Most importantly, 7Li NMR spin-lock transients revealed two overlapping diffusion-induced processes. Overall, activation energies from spin-lock NMR excellently agree with that from conductivity measurements; both techniques yield values around 0.36 eV. The corresponding diffusion coefficients deduced from NMR and conductivity measurements almost coincide. The magnetic spin fluctuations sensed by NMR provide an in-depth look at the elementary jump processes, which can barely be revealed by macroscopic impedance spectroscopy providing average values. In particular, we were able to precisely measure the local hopping barrier (0.20 eV) characterizing forward-backward jumps between the sites 24d and 96h. © 2019 The Author(s)
- ItemCorrigendum to “Dynamics of rural livelihoods and rainfall variability in Northern Ethiopian Highlands” [Clim. Risk Manage. 25 (2019) 100195](S2212096318300378)(10.1016/j.crm.2019.100195)(Amsterdam [u.a.] : Elsevier, 2020) Adamseged, Muluken E.; Frija, Aymen; Thiel, AndreasThe authors regret for not properly acknowledging the contribution of the Consortium Research Program (CRP) on Livestock, led by ILRI with contribution of ICARDA. Funding from the CGIAR Research Program on Livestock (flagship 5 on “Livestock livelihoods and agri-food systems flagship”) is acknowledged for their support of staff time of Dr. Aymen Frija. The authors thank all donors and organizations who globally support the work of the CGIAR Research Program on Livestock through their contributions to the CGIAR system. The authors would like to apologise for any inconvenience caused. © 2020 The Author(s)
- ItemDynamics of rural livelihoods and rainfall variability in Northern Ethiopian Highlands(Amsterdam [u.a.] : Elsevier, 2019) Adamseged, Muluken E.; Frija, Aymen; Thiel, Andreas[No abstract available]
- ItemUnderstanding adaptive capacity of smallholder African indigenous vegetable farmers to climate change in Kenya(Amsterdam [u.a.] : Elsevier, 2020) Chepkoech, Winifred; Mungai, Nancy W.; Stöber, Silke; Lotze-Campen, HermannUnderstanding the adaptive capacity (AC) of farmers is crucial to planning effective adaptation. Action to promote farmers’ AC is required because climate change (CC) is resulting in unpredictable alterations in weather patterns. Based on the sustainable livelihoods framework (SLF), this study explored how access to natural, physical, financial, social and human capitals enhances the AC. Quantitative data from 269 African indigenous vegetable (AIV) farmers in three selected agro-climatic zones in Kenya were analysed. Four indicators in each capital were selected based on previous studies and judgments collected from an expert online ranking survey (n = 35). The Kruskal-Wallis H test and an independent sample t-test were used to test the independence of AC scores and access to the different resources. The findings showed that the majority of farmers (53%) had a moderate AC, while fewer (32%) and (15%) had low or high AC levels respectively. Disparities in adaptive capacity scores were recorded between respondents in terms of their age, marital status and location. Farmers had high access to social capital but low access to financial, natural and human capitals. Female farmers showed lower capacities in the areas of financial, human and natural resources, while their male counterparts had low access to some human and social capitals. Resilient interventions that target individuals with low adaptive capacities are required. © 2020 The Authors
- ItemChallenges of data availability: Analysing the water-energy nexus in electricity generation(Amsterdam [u.a.] : Elsevier, 2019) Larsen, M.A.D.; Petrovic, S.; Engström, R.E.; Drews, M.; Liersch, S.; Karlsson, K.B.; Howells, M.Water is paramount for the operation of energy systems, for securing food supply and for the industry and municipalities. Intersectoral competition for water resources can negatively affect water scarce regions by e.g. power plants shutdowns, poor agricultural yields, and lack of potable water. Future economic and population growth as well as climate change is likely to exacerbate these patterns. However, models used for energy system management and planning in general do not properly include water availability which can lead to improper representations of water-energy interlinkages. The paper initially highlights the water usage rates of current technologies within electricity generation and technologies with a potential to reduce water usage, electricity consumption or GHG emissions. Secondly, the paper presents currently available data on current and future projected water resources as well as data on energy statistics relevant to water-energy nexus studies. Thirdly, implementation cases are presented showing examples of water-energy nexus studies for the data presented. Finally, the paper highlights main challenges in studying the linkage between water and energy. We find a substantial gap in the general availability and quality of regional and global data for detailed quantitative analyses and also identify a need for standardization of formats and data collection methodologies across data and disciplines. An effort towards a coordinated, and sustained open-access data framework with energy sector water usage at fine spatio-temporal scales alongside hydro-climatic observation and model data using common forcings and scenarios for future projections (of climate, socio-economy and technology) is therefore recommended for future water-energy nexus studies. © 2019 The Authors
- ItemEnergy system changes in 1.5 °C, well below 2 °C and 2 °C scenarios(Amsterdam : Elsevier, 2019) Gambhir, Ajay; Rogelj, Joeri; Luderer, Gunnar; Few, Sheridan; Napp, TamarynMeeting the Paris Agreement's goal to limit global warming to well below 2 °C and pursuing efforts towards 1.5 °C is likely to require more rapid and fundamental energy system changes than the previously-agreed 2 °C target. Here we assess over 200 integrated assessment model scenarios which achieve 2 °C and well-below 2 °C targets, drawn from the IPCC's fifth assessment report database combined with a set of 1.5 °C scenarios produced in recent years. We specifically assess differences in a range of near-term indicators describing CO2 emissions reductions pathways, changes in primary energy and final energy across the economy's major sectors, in addition to more detailed metrics around the use of carbon capture and storage (CCS), negative emissions, low-carbon electricity and hydrogen. © 2018 The Authors