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The importance of walking, the most basic form of transportation, is growing. Climate change and the associated warmer temperatures could reduce comfortable walking distances drastically. There is a clear need to better understand how outdoor thermal comfort (OTC) and walking interact. In this work, thermoregulation of the human body is modeled with the two-node model to determine the influence of the microclimate on pedestrians’ OTC. First, the impact of the current microclimate in Zurich on the route choice of pedestrians is analyzed. No significant correlation is found between simulated OTC of walking a particular route and route choices for all trips, but results for longer trips indicate a possible influence of OTC. It is pointed out that the same assessment could be done for other regions, and the results could contribute to more accurate pedestrian modeling. Second, a tool is developed that can estimate OTC-corrected walking distances from any location. The tool is applied to the current climate and future climate scenarios. The results show that, in the future, OTC of pedestrians in Zurich will be severely decreased. Further, the tool can detect where there is potential for and, through its accessibility approach, quantify improvements to the built environment citywide. Future work should focus on enhancing physiological input parameters to the model. This work provides a novel use of the two-node model for walking subjects in a citywide assessment.

Unlike synchrotrons with multiple beamlines, free-electron lasers (FELs) are single-beam facilities, which nevertheless have a number of endstations. The latter requires development of complex radiation transport line, which should be efficient enough to avoid scaling down the FEL capabilities. Keeping the beam shape and radiation power level along the beamline is a challenge because the total length of the FEL radiation transport line can exceed a hundred meters. The FELs around the world differ from each other in both radiation parameters and endstations’ layout requiring individual design of their radiation transport lines. In this work, we describe the 120-m beamline for transporting the radiation of the Novosibirsk FEL facility, consisting of three FELs of the terahertz (THz), far-infrared, and mid-infrared ranges. The radiation of these three FELs is directed to the same beam transport channel, which is able to deliver the radiation to any of 14 endstations already commissioned. To compare the expected beam parameters with the actual ones, the radiation intensity distribution was measured in a number of places of the beamline that are THz radiation outputs for some endstations. Possible causes of the parameters’ mismatching observed for distant endstations are discussed. The problem of radiation absorption by water vapor is considered in detail.

Customizable and technology-friendly functional materials are one of the mainstays of emerging organic electronics and optoelectronics. We show that recombination exciplexes of simple substituted diphenylacetylenes with tertiary amines can be a convenient source of tunable deep-blue emission with possible applications in organic electroluminescent systems. The optically inaccessible exciplexes were produced via recombination of radiation-generated radical ion pairs in alkane solution, which mimics charge transport and recombination in the active layer of practical organic light-emitting diodes in a simple solution-based experiment. Despite varying and rather poor intrinsic emission properties, diphenylacetylene and its prototypical methoxy (donor) or trifluoromethyl (acceptor) monosubstituted derivatives readily form recombination exciplexes with N,N-dimethylaniline and other tertiary amines that produce emission with maxima ranging from 385 to 435 nm. The position of emission band maximum linearly correlates with readily calculated gas-phase electron affinity of the corresponding diphenylacetylene, which can be used for fast computational prescreening of the candidate molecules, and various substituted diphenylacetylenes can be synthesized via relatively simple and universal cross-coupling reactions of Sonogashira and Castro. Together, the simple solution-based experiment, computationally cheap prescreening method, and universal synthetic strategy may open a very broad and chemically convenient class of compounds to obtain OLEDs and OLED-based multifunctional devices with tunable emission spectrum and high conversion efficiency that has yet not been seriously considered for these purposes.

Magnetic field-affected reaction yield (MARY) spectroscopy is a spin chemistry technique for detecting short-lived radical ions. Having sensitivity to transient species with lifetimes as short as nanoseconds, MARY spectroscopy usually does not provide detailed information on their magnetic resonance parameters, except for simple systems with equivalent magnetic nuclei. In this work, the radical anions of two fluorinated diphenylacetylene derivatives with nonequivalent magnetic nuclei and unknown hyperfine coupling constants (AHF) were investigated by MARY spectroscopy. The MARY spectra were found to be resolved and have resonance lines in nonzero magnetic fields, which are determined by the AHFvalues. Simple relationships between the positions of resonance MARY lines and the AHFvalues were established from the analysis of the different Hamiltonian block contributions to the MARY spectrum. The obtained experimental AHFvalues are in agreement with the results of quantum chemical calculations at the density functional theory level.

We suggest a convenient probe exciplex system for studies in radiation spin chemistry based on a novel acceptor-substituted diphenylacetylene, 1-(phenylethynyl)-4-(trifluoromethyl)benzene that has a very short fluorescence lifetime (<200 ps) and low quantum yield (0.01) of intrinsic emission, provides efficient electron capture in alkanes and efficient exciplex formation upon recombination in pair with DMA radical cation, while exhibiting a shifted to red exciplex emission band as compared to the parent system DMA – diphenylacetylene. After chemical, luminescent, radiation and spin-chemical characterization of the new system we used the magnitude of magnetic field effect in its exciplex emission band for experimental estimation of the fraction of spin-correlated radical ion pairs under X-irradiation with upper energy cutoff 40 keV in a set of 11 alkanes. For linear and branched alkanes magnetic field effects and the corresponding fractions are approximately 19–20% and 0.28, while for cyclic alkanes they are lower at 16–17% and 0.22, respectively.

•X-band pulse EPR spectrometer with high throughput and excellent sensitivity in the 8.5-11.5GHz range.•High stability and low noise Fourier Transform measurements.•User-friendly software with real-time phase cycling and FT.