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Unveiling single-particle composition, size, shape, and mixing state of freshly emitted Icelandic dust via electron microscopy analysis
No full textAbstract. Iceland is a significant high-latitude dust source area. Airborne Icelandic dust influences the climate system by interacting with radiation, clouds, and biogeochemical cyclesit also affects snow and ice albedo and air quality. These impacts are sensitive to the dust’s mineralogical, chemical, and physical properties. However, comprehensive measurements and analyses of Icelandic dust particles remain limited. This study examines dust samples collected during a field campaign in the Dyngjusandur desert (August–September 2021) using active and passive aerosol sampling. Over 190 000 individual particles, ranging from 0.1 to 120 µm, were analyzed for their chemical and physical properties using computer-controlled scanning electron microscopy/energy-dispersive X-ray spectroscopy (ccSEM/EDX). Results show heterogeneity in particle size, shape, and composition. The most abundant particle type was medium-Al mixed particles, likely glass-like, comprising 35 %–92 % of the aerosol volume. Sulfate particles, suggesting volcanic contributions, were detected in some samples. Iron (Fe)- and titanium (Ti)-rich particles made up 3.3 % and 6 % of the aerosol volume, respectively, mainly in the size fraction < 1 µm. The median aspect ratio ranged from 1.37 to 1.53, increasing with particle size. Our findings highlight key differences in Icelandic dust compared to Saharan dust, including higher iron and titanium content and a lack of potassium in Icelandic dust. Additionally, Icelandic dust shows a size-dependent increase in aspect ratio, unlike Saharan dust, which remains constant. These observations can improve model simulations that account for the effect of high-latitude dust in the Earth system
The psychology of sentence evaluation: from grammatical illusions to uncertainty profiles
No full textHow do people decide whether a sentence “sounds right” in their native language by judging its syntactic well-formedness independently of meaning? Sentence acceptability judgments reflect not only the speaker\u27s grammatical knowledge but also performance factors including information packaging and processing ease. In this talk, I review what we know about the interaction of these factors, including striking cases of “grammatical illusions” and situations where speakers hesitate or cannot reach a clear judgment when these factors conflict. I then present recent experimental evidence showing that speakers use rating scales strategically whereby scale extremes serve as categorical anchors while the midpoint marks maximal uncertainty. These findings highlight sentence evaluation as a dynamic calibration process and shed new light on how people make linguistic decisions
under uncertainty
Sipalne in transmisijske tehnike za časovno ločljive študije z uporabo koherentnih svetlobnih virov
No full textThe ability to probe and manipulate matter on femtosecond timescales has transformed our understanding of ultrafast phenomena in magnetic, molecular, and condensed matter systems. These rapid processes governed by interactions between charge, spin, and lattice degrees of freedom hold the key to the development of next-generation technologies in information storage, spintronics, and quantum materials. However, unlocking such insights requires advanced light sources capable of delivering coherent, element-specific, and polarization-controlled pulses in the extreme ultraviolet (XUV) and soft X-ray regimes.
This thesis investigates two complementary platforms that have emerged as frontiers in ultrafast science: Free-Electron Lasers (FELs) and High Harmonic Generation (HHG). FELs offer tunable, high-brilliance radiation with programmable polarization, enabling precision experiments at resonance edges of magnetic elements. HHG, on the contrary, provides laboratory-scale access to femtosecond and attosecond pulses and coherent XUV light, ideal for tabletop pump-probe studies. By combining these two platforms, this work addresses both the technical challenges and scientific opportunities in ultrafast magnetization dynamics, light-induced electronic transitions, and angular momentum exchange in light–matter interactions.
The thesis focuses on source optimization strategies, and proof-of-principle experiments ranging from polarization-engineered FEL emission for magnetic dichroism to HHG-based femtosecond Magneto-Optic Kerr Effect (MOKE) and molecular spectroscopy. Through this multiscale approach, it highlights the role of tailored light sources not just as probes but as active tools for manipulating material properties on fundamental timescales. The results lay the groundwork for future studies of complex systems in non-equilibrium regimes, where the interplay of coherence, topology, and ultrafast dynamics defines new states of matter
Categories of hypermagmas, hypergroups, and related hyperstructures. (English. English summary). J. Algebra 676 (2025), 408–474
No full textA note on bias and polarity in Vietnamese
No full textVietnamese has two types of NPIs, simple and complex, and two types of polar questions, yes/no questions and agreement questions. Simple NPIs can occur in both types of polar questions while complex NPIs can occur in yes/no but not in agreement questions. I propose an account for this fact using familiar ingredients of semantic and syntactic analyses. I then discuss some ways in which Vietnamese and English differ with respect to how distinctions in meaning align with distinctions in form
