Characteristic power spectrum of the diffusive interface dynamics in the two-dimensional Ising Model

We investigate properties of the diffusive motion of an interface in the two-dimensional Ising model in equilibrium or nonequilibrium situations. We focused on the relation between the power spectrum of a time sequence of spins and diffusive motion of an interface which was already clarified in one- dimensional systems with a nonequilibrium phase transition like the asymmetric simple exclusion process. It is clarified that the interface motion is a diffusion process with a drift force toward the higher-temperature side when the system is in contact with heat reservoirs at different temperatures and heat transfers through the system. Effects of the width of the interface are also discussed.Comment: 14 pages, 20 figure

Spontaneous Oxidization of an Amorphous Zr_<70>Au_<30> Alloy in Air

An amorphous Zr_Au_ alloy prepared by the melt-quenching technique was found to possess an extremely high oxidization tendency in air even at room temperature, even though the other Zr-based amorphous alloys remain unchanged in the same environment. Upon oxidization, the amorphous structure changes into a duplex crystalline structure consisting of a monoclinic ZrO_2 matrix including fcc Au particles with a size as fine as about 2 nm at an inter-particle spacing of about 4 nm. The oxidization tendency depends strongly on the humidity in air and becomes remarkable with increasing humidity. Furthermore, the oxidization causes a spontaneous pulverization of the ribbon into fine powders consisting of ZrO_2 and Au. The reason for the exceptionally high oxidization only for the Zr_Au amorphous alloy was inferred to be due to a combination effect of a weak attractive bonding nature between Zr and Au and a great catalytic ability of Au

Biexciton binding energy in CuCl quantum dots

Induced absorption from the exciton state to the biexciton state was clearly observed under the site-selective excitation of the inhomogeneously broadened Z3 exciton band in CuCl microcrystallites embedded in NaCl crystals. This allows us to obtain the size-dependent biexciton binding energy in CuCl quantum dots. The binding energy of biexcitons increases with the decrease in their size and its size dependence and bulk value are well represented by the expression 78/a*2+52/a*+33 (meV), where a* is the effective radius of microcrystallites in a unit of nm. The experimental results are compared with an available theoretical result. The enhanced Coulomb interaction in microcrystallites still increases the biexciton binding energy in the large-size regime, where the quantum confinement energy of excitons is not considerable. The size-dependent biexciton binding energy cannot be explained by the weak-confinement model of biexcitons

The Effect of Minimum and Maximum Air Temperatures in the Summer on Heat Stroke in Japan: A Time-Stratified Case-Crossover Study

An increase in the global surface temperature and changes in urban morphologies are associated with increased heat stress especially in urban areas. This can be one of the contributing factors underlying an increase in heat strokes. We examined the impact of summer minimum air temperatures, which often represent nighttime temperatures, as well as a maximum temperature on a heat stroke. We collected data from the records of daily ambulance transports for heat strokes and meteorological data for July and August of 2017–2019 in the Tottori Prefecture, Japan. A time-stratified case-crossover design was used to determine the association of maximum/minimum air temperatures and the incidence of heat strokes. We used a logistic regression to identify factors associated with the severity of heat strokes. A total of 1108 cases were identified with 373 (33.7%) calls originating in the home (of these, 59.8% were the age of ≥ 75). A total of 65.8% of cases under the age of 18 were related to exercise. Days with a minimum temperature ≥ 25 °C had an odds ratio (95% confidence interval) of 3.77 (2.19, 6.51) for the incidence of an exercise-related heat stroke (reference: days with a minimum temperature < 23 °C). The odds ratio for a heat stroke occurring at home or for calls for an ambulance to the home was 6.75 (4.47, 10.20). The severity of the heat stroke was associated with older age but not with air temperature. Minimum and maximum air temperatures may be associated with the incidence of heat strokes and in particular the former with non-exertional heat strokes

Effect of ration level on non-fecal nitrogen excretion of juvenile yellowtail (Seriola quinqueradiata)

Post-feeding non-fecal nitrogen excretion was determined for juvenile yellowtail in a closed tank system. The highest ammonia excretion value was noticeable 2 hr post-feeding, while the urea excretion rate was highest at 4 hr post-feeding. The ammonia excretion rate of fish fed the lowest ration (1.4%bw) was a half of that of fish fed the highest ration (4.1% bw). The equivalent energy value from ammonia was in the range of 8.7 to 18.0 (KJ/kg bw/day) under present feeding condition