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Synopsis Climate change can directly and indirectly affect species distribution. Warming may allow for invasive species, such as apple snails, to migrate to higher latitudes where temperatures are more conducive to their survival and invasion success. Higher temperatures and lower pH ranges have been previously documented to affect the form and function of calcium carbonate shells, which serve many functions, including protection from predators and thermoregulation. This study aimed to quantify differences in the morphology and mechanical properties of invasive apple snail, Pomacea maculata, shells after altering temperature and pH. We mechanically tested shells among three five-week treatments: control, higher temperature, and lower pH. Ultimate Strength increased in shells that were exposed to higher temperatures, but Young’s Modulus and Peak Load did not differ among control, temperature, and pH treatments. Apple snails in higher temperature tanks increased their shell length over the five-week trials. Although snail morphometrics did not differ between sexes, male shells exhibited a higher Peak Load, Young’s Modulus, and Ultimate Strength compared to female shells. Our findings are consistent with previous gastropod studies, in that a lower pH is associated with a decrease in shell size, and higher temperatures yield larger snail shells with a higher ultimate strength. Peak Load did not significantly differ among treatments, which suggests that the cross-sectional area is relatively important when considering this species mechanical performance today and in future climates. Due to the intense nutritional and calcium demands of egg production, female snails may be more susceptible to weakened shells due to low pH environments caused by climate change.

Photo-electrochemical (PEC) devices allow for converting solar energy into chemical energy and for the production of energetically dense solar fuels. Light absorption, charge separation and transport, electrochemical reactions, and ionic transport are required in such devices, all processes happening simultaneously. PEC devices - compared to competing, conventional PV-electrolysis systems - offer the promise of less complexity in design and implementation and more flexibility in their use. Nevertheless, PEC devices' economic and performance competitiveness is not well understood, given their low technology readiness level. No study has considered accurate multi-physical, multi-scale, and multi-dimensional performance models, degradation aspects, and uncertainty in the performance and cost metrics. Addressing some of these unknowns and focusing on the conversion of solar energy into two different solar fuels (H2 from water and CO from CO2), the objective of this thesis is threefold: (i) conduct a system-level techno-economic analysis based on a systematic and physical performance model (including degradation), and address uncertainty via a probabilistic approach (Monte Carlo (MC) method); (ii) based on the insight gained from the techno-economic analysis, identify most promising design and operational principles, substantiated by experimental investigation of an example case to assess practical feasibility; and (iii) develop two intricate multi-dimensional, multi-physical models: one for an innovative PEC device designed to operate with water vapor, and the other for a PEC device utilizing concentrated solar light engaged in the conversion of CO2 to CO. Overall, this thesis provides a combination of experimental demonstration and simulation tools to conduct feasibility studies, predict costs, and provide design guidelines and operational conditions for PEC devices in diverse electrochemical processes. This scope extends the use of PEC devices beyond the traditional liquid water splitting reaction, encompassing applications such as water vapor splitting, energy storage, and CO2 reduction.

The paper presents a computer simulation of the operation of three independent electric drives with a periodic load, connected to a common power supply network. Two cases are considered - operation of electric drives in one phase and in different phases. An analysis of their impact on the electrical supply network is carried out, the results are compared with the permissible Russian standards. An analytical optimization method based on the analysis of power graphs of electric drives with periodic load was considered. The article contains an overview of possible methods for regulating the working phase of the mechanism.

The semiconducting hybrid-organic inorganic halide perovskites have excellent optical and electronic properties that attract the interest of scientists and researchers. Perovskite solar cells have seen the most rising-rate in the chart of solar cell efficiency from 3 to over 25% in less than ten years. In the last three years, most researchers have been focusing on the α-FAPbI3-based perovskite solar cells due to having a lower bandgap (1.45 eV) which is closer to the Shockley-Queisser optimum (1.1- 1.4eV) to gain high efficiency. A distinctive feature of FAPbI3 is that it is more thermally stable compared to MAPbI3. However, the α-FAPbI3 perovskite is not stable at room temperature as it converts to the undesirable Ύ-phase. The 2D- Ruddlesden-Popper-phase-doped 3D FAPbI3 enhancing the stability of the structure, albeit the bandgap is increased rendering a less optimal bandgap. The main achievement of this thesis is discovering that the doping of FAPbI3 with large alkyl ammonium moieties enhances efficiency and stability while maintaining the bandgap of pure α-FAPbI3 perovskite phase. I describe the resulting composition by the formula (A)xFAPbI3, where A represents the large alkyl ammonium iodide species. I study the stabilization of α-FAPbI3 via doping with 5-amino valeric acid hydroiodide (AVAI). By using solid-state NMR, we demonstrate the atomic-level interaction between this molecular modulator and the perovskite lattice and propose a structural model of the stabilized three-dimensional structure, further aided by density functional theory (DFT) calculations. We find the presence of AVAI produces highly crystalline films with large, micrometer-sized grains and enhanced charge-carrier lifetimes, as probed by transient absorption spectroscopy. Optical measurements confirm that there is no effect on the bandgap of FAPbI3 after doping. The devices based on (AVAI)0.25FAPbI3 exhibit superior operational stability in comparison with neat FAPbI3 while achieving power conversion efficiency of 19%. A similar approach based on benzylammonium iodide (BzI) has been used. The structural and optical characterization of films based on (BzI)xFAPbI3 composition demonstrate that there is no 2D phase forming under these conditions. Moreover, solid-state NMR results show BzI interacting on the atomic level with α-FAPbI3 by binding to the 3D perovskite through hydrogen bonding interaction and stabilizing it against the detrimental α-to-Ύ phase transition. Perovskite solar cells based on the (BzI)0.25FAPbI3composition achieve power conversion efficiencies exceeding 20%, which is accompanied by enhanced shelf-life and operational stability, maintaining 80% of the performance after one year at ambient conditions. Finally, films based on (BzI)0.25FAPbI3 compositions are further investigated upon aging under the ambient conditions, as they show an unexpected transition from black to red color without transition to expected yellow Ύ phase, unlike the reference FAPbI3. I perform different measurements to investigate the nature of this red phase as a function of annealing temperature compare these properties to the corresponding Ruddlesden-Popper phase (Bz2FAn-1PbnI3n+1). The red phase was found to be a mixture of a 2D phase (n = 2) Bz2FAPb2I7 and Ύ-FAPbI3, which acts as a barrier to the α-to-Ύ phase transition.

Most households in sub-Saharan Africa rely on wood-based cooking fuels and their number is expected to rise. Despite this, national and subnational energy policies often neglect biomass cooking fuels. A Formative Scenario Analysis process is applied to show how the cooking fuel sector in Kilimanjaro Region (Tanzania) and Kitui County (Kenya) might evolve by 2030. In order to provide relevant knowledge for potential energy policies, this paper aims to identify the main drivers impacting the cooking fuel sector, and to assess and explore current and future demand and supply potential of biomass cooking fuels. Our results show that policies have the potential to substantially impact the future mix of cooking fuels and to foster or hamper the use of efficient cooking fuel technologies. Half of Kilimanjaro Region’s households could be supplied with biogas; in Kitui County, wood-based cooking fuels is likely to remain dominant but improving the efficiency of the technologies would reduce the demand for wood considerably. Hence, we argue that energy policies should explicitly consider biomass cooking fuels and endeavour to make this sector more sustainable and that priority should be given to increasing the sustainability of the biomass cooking fuel sector. Key leverage points to do so are improving the access to improved biomass technologies and capacity building.

Fuel moisture limits the availability of fuel to wildfires in many forest areas worldwide, but the effects of climate change on moisture constraints remain largely unknown. Here we addressed how climate affects fuel moisture in pine stands from Catalonia, NE Spain, and the potential effects of increasing climate aridity on burned area in the Pyrenees, a mesic mountainous area where fire is currently rare. We first quantified variation in fuel moisture in six sites distributed across an altitudinal gradient where the long-term mean annual temperature and precipitation vary by 6-15 °C and 395-933 mm, respectively. We observed significant spatial variation in live (78-162%) and dead (10-15%) fuel moisture across sites. The pattern of variation was negatively linked (r = |0.6|-|0.9|) to increases in vapor pressure deficit (VPD) and in the Aridity Index. Using seasonal fire records over 2006-2020, we observed that summer burned area in the Mediterranean forests of Northeast Spain and Southern France was strongly dependent on VPD (r = 0.93), the major driver (and predictor) of dead fuel moisture content (DFMC) at our sites. Based on the difference between VPD thresholds associated with large wildfire seasons in the Mediterranean (3.6 kPa) and the maximum VPD observed in surrounding Pyrenean mountains (3.1 kPa), we quantified the "safety margin" for Pyrenean forests (difference between actual VPD and that associated with large wildfires) at 0.5 kPa. The effects of live fuel moisture content (LFMC) on burned area were not significant under current conditions, a situation that may change with projected increases in climate aridity. Overall, our results indicate that DFMC in currently fire-free areas in Europe, like the Pyrenees, with vast amounts of fuel in many forest stands, may reach critical dryness thresholds beyond the safety margin and experience large wildfires after only mild increases in VPD, although LFMC can modulate the response.

Abstract Increases in temperatures and atmospheric CO2 concentration influence the growth performance of trees worldwide. The direction and intensity of tree growth and physiological responses to changing climate do, however, vary according to environmental conditions. Here we present complex, long-term, tree-physiological responses to unprecedented temperature increase in East Asia. For this purpose, we studied radial growth and isotopic (δ13C and δ18O) variations using tree-ring data for the past 100 yr of dominant Quercus mongolica trees from the cool-temperate forests from Hallasan, South Korea. Overall, we found that tree stem basal area increment, intercellular CO2 concentration and intrinsic water-use efficiency significantly increased over the last century. We observed, however, short-term variability in the trends of these variables among four periods identified by change point analysis. In comparison, δ18O did not show significant changes over time, suggesting no major hydrological changes in this precipitation-rich area. The strength and direction of growth–climate relationships also varied during the past 100 yr. Basal area increment (BAI) did not show significant relationships with the climate over the 1924–1949 and 1975–1999 periods. However, over 1950–1974, BAI was negatively affected by both temperature and precipitation, while after 2000, a temperature stimulus was observed. Finally, over the past two decades, the increase in Q. mongolica tree growth accelerated and was associated with high spring–summer temperatures and atmospheric CO2 concentrations and decreasing intrinsic water-use efficiency, δ18O and vapour pressure deficit, suggesting that the photosynthetic rate continued increasing under no water limitations. Our results indicate that the performance of dominant trees of one of the most widely distributed species in East Asia has benefited from recent global changes, mainly over the past two decades. Such findings are essential for projections of forest dynamics and carbon sequestration under climate change.

The most extreme environments are the most vulnerable to transformation under a rapidly changing climate. These ecosystems harbor some of the most specialized species, which will likely suffer the highest extinction rates. We document the steepest temperature increase (2010-2021) on record at altitudes of above 4,000 m, triggering a decline of the relictual and highly adapted moss Takakia lepidozioides. Its de-novo-sequenced genome with 27,467 protein-coding genes includes distinct adaptations to abiotic stresses and comprises the largest number of fast-evolving genes under positive selection. The uplift of the study site in the last 65 million years has resulted in life-threatening UV-B radiation and drastically reduced temperatures, and we detected several of the molecular adaptations of Takakia to these environmental changes. Surprisingly, specific morphological features likely occurred earlier than 165 mya in much warmer environments. Following nearly 400 million years of evolution and resilience, this species is now facing extinction.