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Agroforestry as land-based carbon dioxide removal in central Europe: tensions between institutions, interests, and ideas hindering scaling up
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Suppressing halide segregation in wide‐bandgap perovskite absorbers by transamination of formamidinium
No full textAll-perovskite tandem solar cells are emerging at a fast rate because of their potential to exceed efficiencies of Si-perovskite tandems, in combination with faster manufacturing, lower cost, and the ability to be processed on flexible substrates. Mixing halides is a key to achieve wide-bandgap absorbers, which however suffer from halide segregation under illumination, resulting in lowering of the bandgap. To tackle this problem, butylamine (BA) has been added to the perovskite precursor solution and is found to react with the formamidinium (FA) cation, producing N-butylformamidinium (BuFA+), which accumulates at the perovskite surface and grain boundaries. The creation of the BuFA cation results in suppressed halide segregation and improved crystallization. Density functional theory calculations propose the reduction of halide defect formation upon the addition of BA, being a key to stabilize mixed-halide perovskites. Lastly, we observe a more stable performance of single junction p–i–n perovskite solar cells with the addition of BA under constant illumination at 65 °C
PyPSA-Earth sector-coupled: a global open-source multi-energy system model showcased for hydrogen applications in countries of the Global South
No full textThis study presents sector-coupled PyPSA-Earth: a novel global open-source energy system optimization model that incorporates major demand sectors and energy carriers in high spatial and temporal resolution, to enable energy transition studies worldwide. The model includes a workflow that automatically downloads and processes the necessary demand, supply and transmission data to co-optimize investment and operation of energy systems of countries or regions of Earth. The workflow provides the user with tools to forecast future demand scenarios and allows for custom user-defined data in several aspects. Sector-coupled PyPSA-Earth introduces novelty by offering users a comprehensive methodology to generate readily available sector-coupled data and model of any region worldwide, starting from raw and open data sources. The model provides flexibility in terms of spatial and temporal detail, allowing the user to tailor it to their specific needs. The capabilities of the model are demonstrated through two showcases for Egypt and Brazil. The Egypt case quantifies the relevant role of PV, exceeding 35 GW, and electrolysis in Suez and Damietta regions, for meeting 16% of the EU hydrogen demand. Complementarily, the Brazil case confirms the model’s ability in handling hydrogen planning infrastructure, including repurposing of existing gas networks which results in 146 M€ lower costs than building new pipelines. The results prove the suitability of sector-coupled PyPSA-Earth to meet the needs of policymakers, developers, and scholars in advancing the energy transition. The authors invite the interested individuals and institutions to collaborate in the future developments of the model within PyPSA meets Earth initiative
A novel method based on composite alteration to reduce the shrinkage of the sintering process of additively manufactured parts
No full textTo tackle the challenge of high shrinkage in sintered additively manufactured parts, a novel approach involving the modification of the printing composition through the incorporation of glass fibers was proposed. Experimental evaluations demonstrated the effectiveness of this method, revealing a substantial improvement in the dimensional and geometrical accuracy of the fabricated parts. By incorporating 12 % short glass fibers into the composition, the shrinkage was significantly reduced, achieving an impressive 0.1 %
Parameters influencing semi-batch reverse osmosis - Model based analysis
No full textSemi-batch closed loop reverse osmosis (CLRO) provides an alternative to overcome the challenges associated with the recovery rate, brine volume and specific energy consumption (SEC) in conventional RO. A flexible modelling tool is developed to size a CLRO system and predict its performance under various operating conditions. This tool was used for designing a pilot scale CLRO system, which was experimentally validated for brackish water treatment in Qatar. The predictions were within 5 % accuracy when compared to experimental results. The influence of system parameters, such as the feed ratio (FR), the concentrate recirculation (Q̇C_RCL) and the recovery rates of the RO membrane in plug flow (PF) mode (RPF) and closed loop (CL) mode (RCL) on performance are analysed to deepen process understanding. A system with a 4-inch LG SW 4040 R treating 25 g/l of artificial NaCl solution is considered for the examining the impact of these key parameters. Assuming an ideal plug flow without any mixing, the results show that the FR has little impact on system performance. An increase in Q̇C_RCL and in RCL results in significant increase in flux and permeate quality with a slight increase in SEC. RPF has a little impact on overall SEC of the system. To reach a high overall recovery rate with low SEC, low RPF, RCL and low Q̇C_RCL are necessary. If permeate quality is a concern, low RPF, high RCL, and high Q̇C_RCL are required
Rational design, synthesis, and evaluation of novel polypharmacological compounds targeting NaV1.5, KV1.5, and K2P channels for atrial fibrillation
No full textAtrial fibrillation (AF) involves electrical remodeling of the atria, with ion channels such as NaV1.5, KV1.5, and TASK-1 playing crucial roles. This study investigates acetamide-based compounds designed as multi-target inhibitors of these ion channels to address AF. Compound 6f emerged as the most potent in the series, demonstrating a strong inhibition of TASK-1 (IC50 ∼ 0.3 μM), a moderate inhibition of NaV1.5 (IC50 ∼ 21.2 μM) and a subtle inhibition of KV1.5 (IC50 ∼ 81.5 μM), alongside unexpected activation of TASK-4 (∼ 40% at 100 μM). Functional assays on human atrial cardiomyocytes from sinus rhythm (SR) and patients with AF revealed that 6f reduced action potential amplitude in SR (indicating NaV1.5 block), while in AF it increased action potential duration (APD), reflecting high affinity for TASK-1. Additionally, 6f caused hyperpolarization of the resting membrane potential in AF cardiomyocytes, consistent with the observed TASK-4 activation. Mathematical modeling further validated its efficacy in reducing AF burden. Pharmacokinetic analyses suggest favorable absorption and low toxicity. These findings identify 6f as a promising multi-target therapeutic candidate for AF management
Grapevines and trees: a biodiversity study of microbiomes in an established temperate agroforestry system
No full textBiodiversity is threatened particularly in perennial crop cultivation such as fruit trees or grapevines. If established, agroforestry has the potential to increase biodiversity by providing a higher habitat heterogeneity at the example of grapevine (Vitis vinifera L. cv. Riesling) cultivated together with oak or poplar trees for 12 years. Together with the rhizosphere microbiome, the root metabolome was quantified as an indicator of root exudation. Since the root metabolome does not fully align with the exudate metabolome, we are using the root metabolome as a proxy for the exudate metabolome. The results reveal that co-cultivation of grapevine with trees reduces the nutrient availability in the soil and changes the root metabolome of both, grapevine and trees with a more distinct effect of trees on grapevine than vice versa, particularly for oak. Apparently, root-to-root signalling takes place between trees and grapevine. Co-cultivation of grapevine and oak trees also enhanced the alpha diversity of the microbiome. Correlation analysis revealed strong positive correlations between distinct microbial families and metabolites enriched in the roots of Riesling. Thus, microbiome analyses support the view that root-to-root interaction in mixed cultivation of grapevine with trees is mediated by root exudation
Fight to survive: marchantia synthesizes newly identified metabolites in response to wounding
No full textPlants sense and adjust to continuously changing environmental cues. Whether these cues are abiotic like temperature and light, or biotic like soil microorganisms, plant responses to all of them are centrally coordinated through phytohormones. The field of phytohormone research has come a long way since the beginning of the last century when “phytohormone” simply meant auxin (Kende and Zeevaart 1997). Besides a group of “classic” hormones—auxin, gibberellin, ethylene, cytokinin, and abscisic acid—the field currently includes an extended group of small-molecule phytohormones that regulate different aspects of plant life and that arose over the course of their evolution (Kende and Zeevaart 1997; Gasperini and Howe 2024).In terms of signaling pathways, one of the best understood phytohormones is jasmonate (JA). In angiosperms, JA conjugated to isoleucine (JA-Ile) is a major regulator of biotic and abiotic plant stress responses as well as developmental pathways (Chini et al. 2016). It controls diverse processes, from the scent of jasmine flowers to the regulation of complex transcription networks (Chini et al. 2016; Howe et al. 2018). The wide range of responses tightly regulated by JAs is a result of increasing evolutionary complexity and redundancy in its regulatory pathway. While JAs were already present in the earliest land plants and while different plant lineages share JA basic signaling pathway characteristics, the starting molecule that activates the pathway is different for different species (Chini et al. 2023). The lineages that led to Marchantia polymorpha and Arabidopsis thaliana diverged 450 million years ago. While in bryophyte Marchantia, dinor-12-oxo-phytodienoic acid (dn-OPDA) is the activating JA; in angiosperm Arabidopsis, the JA-Ile conjugate acts as the activator (Fig)