Nicolaus Copernicus University in Toruń (Polish: Uniwersytet Mikołaja Kopernika w Toruniu, UMK) is located in Toruń, Poland. It is named after Nicolaus Copernicus, who was born in Toruń in 1473.
The growing demand for efficient waste heat recovery has intensified the search for high-performance thermoelectric (TE) materials with a figure of merit (ZT) above 2.5. In this study, first-principles calculations based on DFT combined with Boltzmann transport theory were employed to investigate the structural, electronic, thermal, and thermoelectric properties of synthesized Mg3NF3 and newly predicted halide perovskites X3NI3 (X = Sr, Ba). Structural stability was verified through geometric optimization, negative formation energies, elastic constants, and phonon dispersion analyses. The band gaps corresponding to Mg3NF3, Sr3NI3, and Ba3NI3 were estimated to be 6.811, 1.279, and 0.807 eV (HSE06), respectively, which are insulating and semiconducting, respectively. In contrast, Sr3NI3 and Ba3NI3 show remarkably low thermal conductivities (0.43 and 0.45 Wm-1K-1, respectively) combined with large Seebeck coefficients (123.89 and 135.10 mu V/K), yielding promising ZT values of 2.5 and 2.6 at 1000 K. The combination of mechanical robustness, thermal stability, and excellent thermoelectric performance positions Ba3NI3 and Sr3NI3 as promising candidates for high-temperature thermoelectric applications. In contrast, Mg3NF3, despite its modest ZT value, exhibits a high Debye temperature and melting point, indicating strong resistance to thermal degradation and suitability for high-temperature environments.
The development of efficient thermoelectric materials for direct waste heat–to–electricity conversion remains a major challenge, particularly for high-temperature applications. In this paper, a systematic first-principles examination of the structural, electronic, elastic, thermal and thermoelectric characteristics of double perovskite oxides, Ba2XReO6 (X = Li, Rb, Cs), is conducted using the density functional theory, alongside Boltzmann transport theory. Structural optimization proves that all compounds are thermodynamically stable in the cubic Fm3̅m phase with negative formation energies. Furthermore, ab initio molecular dynamics simulations performed at 300 K confirm the dynamical stability of the optimized structures. The electronic structure analysis reveals semiconducting behavior in Ba2CsReO6, Ba2LiReO6, and Ba2RbReO6, all exhibiting indirect and narrow band gaps, which are ideal characteristics for thermoelectric transport. The elastic constants obtained and used have met the Born stability requirements, indicating mechanical stability and ductile behavior. A systematic decrease in Debye temperature, melting temperature, and lattice thermal conductivity with increasing A-site ionic radius led to ultralow lattice thermal conductivity of Ba2RbReO6 and Ba2CsReO6. Thermoelectric transport calculations show positive Seebeck coefficients and enhanced power factors at elevated temperatures. Of the investigated compounds, the Ba2RbReO6 has the largest thermoelectric figure of merit (ZT), owing to an optimum balance between electrical conductivity and reduced thermal conductivity. Overall, our results suggest that Ba2XReO2, particularly Ba2RbReO2, are promising candidates for high-temperature thermoelectric applications.
Photosensitizers play a pivotal role as photoanode materials in dye-sensitized solar cells (DSSCs). However, systems that offer superior water-solubility and provide good optical absorption while allowing facile synthesis are highly sought-after. Here, a water-soluble dinuclear oxovanadium(V) Schiff-base complex (V-SBC) is synthesized, and its physicochemical properties and its photoconversion performance as a DSSC photosensitizer are examined using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, spectrophotometry, photoluminescence measurements, scanning electron microscopy, and electrical measurements. We show that the V-SBC exhibits a major V5+ oxidation state of coordinated vanadium ions and chemical bonds of the dinuclear structure, as resolved using crystallographic diffraction. The onset of optical absorption at about 2.43 eV and a 3.62 ns photoelectron lifetime is determined, while the defect-laden nature of V-SBC is evidenced by additional near-band edge and broad donor–acceptor or deep-level emissions of respective energies at about 2.36 and 2.20 eV. Photoconversion performances of DSSCs sensitized with the V-SBC and DSSCs co-sensitized with the V-SBC and aloe latex solid (ALS) are evaluated. Without specific optimization, the electrical characteristics of FTO/TiO2/V-SBC/Electrolyte/Pt/FTO DSSCs yield an open-circuit voltage (VOC) of 0.204 V, a short-circuit current density (JSC) of 0.328 mA.cm–2, and a fill factor (FF) of 47.1
Aim Taxonomic identification, population demographics and genetic structure reconstruction of the historical Lake Ladoga sturgeon population, followed by assessment of admixture and gene flow of Atlantic and European sturgeons within the Baltic and broader European context.Location Archaeological site at Staraya Ladoga (Zemlyanoe Gorodishche), encompassing samples from Lake Ladoga and the Volkhov River in north-western Russia.Taxon Atlantic (Acipenser oxyrinchus) and European (A. sturio) sturgeons.Methods A total of 7130 sturgeon bones dated to the 9th-10th centuries CE were morphologically examined to determine their species identity. Age (n = 51) and catch season (n = 33) were reconstructed. Genetic analyses of remains from Ladoga (n = 45) and other European localities (n = 48) were conducted using three mitochondrial DNA (mtDNA) fragments, seven microsatellite loci (STRs), and one SNP-informative microsatellite locus (Aox23) to assess species composition, ancestry, admixture, and gene flow with other sturgeon populations, including published historical Baltic (n = 62) and contemporary samples from France and Canada (n = 184).Results Age analysis showed a bias toward large, older individuals that were likely caught during spring-early summer spawning migrations. The Atlantic sturgeon was the dominant species, based on both morphology (83%) and genetic analysis. None of the individuals were identified as pure European sturgeon or first-generation hybrids. Only 5% of STR alleles showed European sturgeon ancestry, and 11% of individuals carried its diagnostic mtDNA haplotype. Admixed samples were found in the Ladoga region, Baltic Sea and North Sea.Main Conclusions Our findings revealed the historical dominance of the Atlantic sturgeon in Lake Ladoga and across Northern Europe including the North Sea. It also sheds new light on the colonisation process, suggesting a rapid Atlantic sturgeon expansion into north-eastern Europe with minimal hybridization with European sturgeon during this phase. This study highlights past connectivity among sturgeon stocks in Europe and underscores the importance of preserving migration routes and habitats to maintain gene flow, which is critical for effective sturgeon restoration.
Epistemic asymmetries (EAs) arise in ordinary situations where one person really knows something, or has good reason to think they know it, while another person does not have equally strong grounds for the same belief. These asymmetries range from trivial to highly problematic in practice, presenting a significant challenge in cases where verifying another person's assertions is extremely difficult - such as in layperson-expert communication. This article argues that EAs represent a fundamentally political problem that political theorists often overlook or misinterpret. Addressing this oversight, the article demonstrates how incorporating EAs into political theory provides three significant contributions: it offers a compelling explanation for the emergence of the post-truth era, it charts new pathways for critiquing epistocracy, and reimagines the narrative and strategic framework of liberal democrats.
