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Abstract The Primordial Inflation Explorer (PIXIE) is an Explorer-class mission concept to measure the energy spectrum and linear polarization of the cosmic microwave background (CMB). A single cryogenic Fourier transform spectrometer compares the sky to an external blackbody calibration target, measuring the Stokes I, Q, U parameters to levels ∼200 Jy/sr in each 2.65° diameter beam over the full sky, in each of 300 frequency channels from 28 GHz to 6 THz. With sensitivity over 1000 times greater than COBE/FIRAS, PIXIE opens a broad discovery space for the origin, contents, and evolution of the universe. Measurements of small distortions from a CMB blackbody spectrum provide a robust determination of the mean electron pressure and temperature in the universe while constraining processes including dissipation of primordial density perturbations, black holes, and the decay or annihilation of dark matter. Full-sky maps of linear polarization measure the optical depth to reionization at nearly the cosmic variance limit and constrain models of primordial inflation. Spectra with sub-percent absolute calibration spanning microwave to far-IR wavelengths provide a legacy data set for analyses including line intensity mapping of extragalactic emission and the cosmic infrared background amplitude and anisotropy. We describe the PIXIE instrument sensitivity, foreground subtraction, and anticipated science return from both the baseline 2-year mission and a potential extended mission.

Universal access to energy is a global priority, increasingly delivered through grid-tied and off-grid infrastructure. However, energy policies frequently conflate universal access with extending and subsidising networked electricity, resulting in technology-dominated approaches. Rapid urbanisation in the global south has outstripped infrastructure capacity, where urban dwellers’ access to affordable, reliable, and sustainable forms of energy are precarious. This failure to reflect human needs and societal expectations alongside technical considerations is threatening the sustainability of urban energy transitions. This paper draws from qualitative data with low-income urban dwellers and municipal policymakers to critically examine South Africa’s energy access policies. We demonstrate how prioritising ‘electricity for all’ via grid connections fails to deliver universal access to affordable energy. First, the state’s emphasis on extending and subsidising networked electricity prioritises proximity to grid connections rather than access to energy services, and permanently excludes households living in un-serviceable structures/settlements. Second, limited community participation produces a policy that ignores low-income households’ urban practices and creates perverse incentives to distort energy consumption. We argue that delivering an urban energy transition that is economically feasible, locally appropriate and socially desirable requires policy expansion beyond physical delivery, working with targeted communities on policy development, knowledge exchange, and capacity building.

Data availability: The authors do not have permission to share data. The adaptability of hydrogen across sectors such as transportation, heavy industry, and its support for intermittent renewable generation through flexible storage has sparked growing interest in electrolysis-based hydrogen production. While large-scale electrolyser integration enhances network stability by aiding constraint management and reducing renewable curtailment through storage, it also places considerable demand on electricity networks. This makes understanding the role of electrolyser deployment on distribution networks (DNs) increasingly crucial. While existing studies on hydrogen-integrated DNs often target specific operational costs or isolated constraints, they typically lack a comprehensive view that considers broader economic, operational, and environmental impacts. This study offers an extensive analysis across these dimensions, exploring diverse hydrogen supply configurations, including hydrogen pipeline and storage unit availability, within a real UK DN to provide a practical perspective. This study introduces a conflicting multi-objective function that improves load factor (LF) by 85.516% and reduces power loss by 22.947%, all while managing operational costs effectively. Findings underline that deploying electrolysers with efficient management algorithms can significantly enhance the operations of DNs. Additionally, this paper contributes to the field by detailing recent UK-based electrolysis projects, providing insights into the future of hydrogen–electricity coupled multi-energy networks. This research was supported by Engineering and Physical Sciences Research Council (EPSRC) Grant Reference EP/W524542/1. The authors thank UK Power Networks DSO for providing data during the corresponding author’s employment, which contributed significantly to the analysis presented in this study.

Abstract Background By exceeding planetary environmental boundaries, multiple global crises have become imminent in the 21st century. The healthcare system is a contributor to the climate crisis, accounting for approximately 5% of greenhouse gas emissions in Western countries. In anaesthetic clinics, desflurane, a highly potent greenhouse gas and volatile anaesthetic with no compelling indications, accounts for up to two thirds of total emissions. Its use can be drastically reduced using simple measures. In the present study, we investigated whether a relevant and timely reduction in use could be achieved by dismounting desflurane vaporisers and providing information to the team without restricting its use. Methods The study was conducted in a German university hospital with approximately 1250 beds, over a 12-month period between 2021 and 2022, with a comparison to the corresponding periods of the previous years up to 2017. The interventions were, first, the removal of desflurane vaporisers, and second, staff education on the climate impact of volatile anaesthetics. The primary outcome variable was the reduction of hypnotic-related emissions in CO2 equivalents per anaesthetic procedure. Results Prospective data collection and interventions were conducted from 28 March 2021 to 27 March 2022. The amount of CO2 equivalent emissions per procedure in the form of volatile anaesthetics was reduced by 86% compared with the year before the interventions (p < 0.001). Interestingly, there was already a 52.1% reduction in the year before the procedure (p < 0.001). There were no significant changes in the use of sevoflurane or propofol. Hypnotic-related costs decreased by €14,549, whereas extubation time did not change significantly. Conclusions Removal of desflurane vaporisers and staff training can quickly and significantly reduce the emissions of an anaesthesia department in a large German teaching hospital. This may also reduce the costs. Trial registration The trial was registered with the German Clinical Trials Register, identifier DRKS00024973 on 12/04/2021.

Shifts in the timing of phenological events across many taxa and ecosystems are a result of climate change. Within a trophic network, phenological mismatches between interlinked species can have negative impacts for biodiversity, ecosystems, and the trophic network. Here we developed interaction indices that quantify the level of synchrony and asynchrony among groups of species in three interlinked trophic levels, as well as accounting for a dynamic representation of meteorology. Insect first flight, vegetation green-up and arrival of migrant birds were the phenological indicators, obtained from a combination of spatially and temporally explicit species observations from citizen science programmes and remote sensing platforms (i.e., Landsat). To determine phenological shifts in interlinked taxa we created and applied several phenological indices of synchrony-asynchrony, combining information from the phenological events and critical time windows of meteorological variables. To demonstrate our method of incorporating a meteorological component in our new interaction index, we implemented the relative sliding time window analysis, a stepwise regression model, to identify critical time windows preceding the phenological events on a yearly basis. The new indices of phenological change identified several asynchronies within trophic levels, allowing exploration of potential interactions based on synchrony among interlinked species. Our novel index of synchrony-asynchrony including a meteorological dimension could be highly informative and should open new pathways for studying synchrony among species and interaction networks.

A persistent concealed non-Kekulé nanographene featuring two phenalene units fused in a cis configuration to a perylene core was successfully synthesized in solution and characterized.

Abstract Aqueous zinc batteries are attractive for large-scale energy storage due to their inherent safety and sustainability. However, their widespread application has been constrained by limited energy density, underscoring a high demand of advanced cathodes with large capacity and high redox potential. Here, we report a reversible high-capacity six-electron-conversion Se cathode undergoing a ZnSe↔Se↔SeCl4 reaction, with Br−/Brn − redox couple effectively stabilizes the Zn | |Se cell. This Se conversion, initiated in a ZnCl2-based hydrogel electrolyte, presents rapid capacity decay (from 1937.3 to 394.1 mAh gSe −1 after only 50 cycles at 0.5 A gSe −1) primarily due to the dissolution of SeCl4 and its subsequent migration to the Zn anode, resulting in dead Se passivation. To address this, we incorporate the Br−/Brn − redox couple into the Zn | |Se cell by introducing bromide salt as an electrolyte additive. The generated Brn − species acts as a dead-Se revitalizer by reacting with Se passivation on the Zn anode and regenerating active Se for the cathode reaction. Consequently, the cycling stability of the Zn | |Se cell is improved, maintaining 1246.8 mAh gSe −1 after 50 cycles. Moreover, the Zn | |Se cell exhibits a specific capacity of 2077.6 mAh gSe −1 and specific energy of 404.2 Wh kg−1 based on the overall cell reaction.