A method of estimating water vapor (propagation delay due to water vapor) using digital terrestrial broadcasting waves is proposed. Our target is to improve the accuracy of numerical weather forecast ...for severe weather phenomena such as localized heavy rainstorms in urban areas through data assimilation. In this method, we estimate water vapor near a ground surface from the propagation delay of digital terrestrial broadcasting waves. A real‐time delay measurement system with a software‐defined radio technique is developed and tested. The data obtained using digital terrestrial broadcasting waves show good agreement with those obtained by ground‐based meteorological observation. The main features of this observation are, no need for transmitters (receiving only), applicable wherever digital terrestrial broadcasting is available and its high time resolution. This study shows a possibility to estimate water vapor using digital terrestrial broadcasting waves. In the future, we will investigate the impact of these data toward numerical weather forecast through data assimilation. Developing a system that monitors water vapor near the ground surface with time and space resolutions of 30 s and several kilometers would improve the accuracy of the numerical weather forecast of localized severe weather phenomena.
Key Points
A method of estimating water vapor (propagation delay due to water vapor) using digital terrestrial broadcasting waves is proposed
A real‐time measurement system is developed with a SDR technique, which can measure the propagation delay in millimeter order
The humidity estimated by this method shows good agreement with that obtained by ground‐based meteorological observation
Synopsis Profiles of 2.8 MeV H+ microbeam extracted from a single tapered glass capillary optics were meas-ured by two methods for a future irradiation to an outer organ of insect target. The halo ...component was analyzed to be 575 μm in full width at half maximum (FWHM) at a plastic tracking detector CR-39 located 1 mm down-stream of the capillary. The core component was examined by knife-edge method according to the ion energies. The profiles consisting of more energy-loss events have wider FWHM, which can be reduced by Al thin layers.
Spin fluctuations were studied over a wide momentum (hQ) and energy (E) space in the frustrated d-electron heavy-fermion metal LiV2O4 by time-of-flight inelastic neutron scattering. We observed the ...overall Q-E evolutions near the characteristic Q=0.6 A-1 peak and found another weak broad magnetic peak around 2.4 Angstrom-1. The data are described by a simple response function, a partially delocalized magnetic form factor, and antiferromagnetic short-range spatial correlations, indicating that heavy-fermion formation is attributable to spin-orbit fluctuations with orbital hybridization.
Color vision is an important characteristic of primates and, intriguingly, Neotropical monkeys are highly polymorphic for this trait. Recent field studies have challenged the conventional view that ...trichromatic color vision is more adaptive than dichromatic color vision. No study has investigated the pattern of genetic variation in the long to middle wavelength-sensitive (L-M or red-green) opsin gene as compared with that of other genomic regions (neutral references) in wild populations of New World monkeys to look for the signature of natural selection. Here, we report such a study conducted on spider monkeys and capuchin monkeys inhabiting Santa Rosa National Park, Costa Rica. The nucleotide sequence of the L-M opsin gene was more polymorphic than the sequences of the neutral references, although the opsin-gene sequences were not more divergent between the two species than were the sequences of the neutral references. In a coalescence simulation that took into account the observed nucleotide diversity of the neutral references, the Tajima's D value of the L-M opsin gene deviated significantly in a positive direction from the expected range. These results are the first to statistically demonstrate balancing selection acting on the polymorphic L-M opsin gene of New World monkeys. Taking the results of behavioral and genetic studies together, the balancing selection we detected may indicate that coexistence of different color-vision types in the same population, also characteristic of humans, is adaptive.
Inelastic neutron scattering measurements of magnetic excitations in hole-doped high-Tc cuprates La2−xSrxCuO4 (x=0 and 0.075) have been performed over a wide temperature range of 5–500 K extending ...beyond the pseudogap temperature of ∼360 K for x=0.075. For x=0, the two-dimensional spin-wave excitations at low temperatures are thermally robust and the dispersion is slightly softened on heating up to T=400 K. For x=0.075, the spin-wave-like excitations in the upper part of the hourglass-shaped dispersion remain at T=300 K. However, further heating above T=400 K induces a broad ridge centered at (1/2,1/2); thereby the hourglass-shaped dispersion becomes blurred above the pseudogap temperature. The localized spin nature of magnetic excitations below T* suggests that the pseudogap is related to the proximity to a Mott insulator rather than being a precursor of Cooper pairs.
Ag-nanoparticle thin films on a polyimide substrate were subjected to microwave sintering by use of a single-mode waveguide applicator. A two-step sintering process was employed. First, at low ...conductivities of the film, the film sample was placed at the site of the maximum electric field and subjected to microwave irradiation. Second, when the conductivity of the film increased, the film sample was placed at the site of the maximum magnetic field and again subjected to microwave irradiation. The microwave sintering process was completed within 1.5 min, which is significantly lower than the time required for the oven heating process. The resulting conductivity of the film, albeit only 30% of that of the bulk material, was seven times that of a film annealed at the same temperature in a furnace. Scanning electron microscopy images revealed that the nanoparticles underwent both grain necking and grain growth during microwave sintering. In addition, this sintering process was equivalent to the oven heating process performed at a 50 °C higher annealing temperature. An electromagnetic wave simulation and a heat transfer simulation of the microwave sintering process were performed to gain a thorough understanding of the process.
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