Population Density Measurements in a Supersonic Freejet Expansion Flow of an O₂-seeded Ar Plasma

The population densities of O(3p³P) and O(3p⁵P) were measured along the freejet centerline of an O₂-seeded Ar plasma, which was such that oxygen gas was seeded into a pre-ionized argon plasma. The ratio of the measured population densities of the 3p³P and 3p⁵P states was compared with the predicted ratio, which was determined from a steady state population assumption of O(3p⁵P), over the whole region of the freejet. The comparison showed that on the condition Nₑ=1.8×10¹³-1.7×10¹²cm⁻³ Tₑ= 3000-900 K and p＝48-0.19 Pa, the 3p⁵P state is populated by electron-collisional de-excitations of the 3p³P state, rather than by quenching of the 3p³P state by the ground state argon. Further, the 3p⁵P state is de-populated by electron-collisional de-excitations rather than by radiative de-excitations

Experimental Studies on the Concentrations of Subjectively Equivalent Irritation for Odorants

Discussion of non-olfactory “irritation”, which is caused by the excitement of the trigeminal nerve, has important implications for odor pollution. The main purpose of this study is to work out the mechanisms for the generation of non-olfactory irritation, and the sensory characteristics of the perceived irritation. Concentrations of subjectively equivalent irritation (CE) of 16 odorous compounds were measured by the sensory test. The relations between the CE and the physicochemical properties of the compounds were shown and discussed. It was found that the CE of dissociated compounds is much lower than that of undissociated compounds. And among the dissociated compounds, the acidic ones have a lower CE than the basic compounds. The CE of acrolein, which is an unsaturated compound, was the lowest among all the compounds used in this experiment. The delay time, i.e. time until the sensation of irritation after inhaling, was longer for acrolein gas than for other gases. Therefore, the mechanism for generating sensory irritation by the acrolein gas may be different from that of other gases. From analysis on the basis of relation to some physicochemical properties, it was concluded that the electrophilic reactivity of the acrolein molecule may be related to the generation of sensory irritation. In the case of dissociated compounds, the CE is related to the dissociation constants of the compounds. In other words, the larger the acidic and basic dissociation constants (Ka and Kb) are, the lower the CE becomes. Key Words : Sensory test, Odorous irritant, Concentration for subjectively equivalent irritation, Physicochemical properties, Dissociation constan

Ejecta Size Distribution Resulting from Hypervelocity Impact of Spherical Projectiles on CFRP Laminates

AbstractThe size distributions of ejecta resulting from projectile perforation of CFRP (carbon fiber reinforced plastic) laminates were examined. The shape of the ejecta cone and the debris cloud was observed using a high-speed video camera. The ejecta fragments were collected from the test chamber after impact experiments. The number of fragments ejected on the front side of the target was altered by the impact velocity. Conversely, regardless of impact velocity, the number of fragments ejected on the rear side of the target was almost the same.The results were also compared with the results of NASA's breakup model. The slope on the cumulative number distribution curve of characteristic length, LC, was almost the same as that of NASA's breakup model. The area-to-mass ratio distribution of ejecta fragments from CFRP laminates ranged within and above the area surrounded by ±3σ of NASA's breakup model

Do thin filaments of smooth muscle contain calponin? A new method for the preparation

AbstractA new method for the preparation of smooth muscle thin filaments which include calponin was established. We found that calponin readily separated from thin filaments in the presence of 10 mM ATP. By preventing thin filament extract from exposing to ATP, we obtained thin filaments which contained actin, tropomyosin, caldesmon and calponin in molar ratios of 7:0.9:0.6:0.7. We studied myosin Mg-ATPase activity by using the thin filaments in comparison with classical thin filaments prepared by the method of Marston and Smith, which contained the same amounts of caldesmon and tropomyosin as our thin filaments but lost almost all calponin. The presence of calponin reduced the Vmax value for thin filament-activated myosin Mg-ATPase activity by 33% without a significant change in Km value. These findings suggest that calponin inhibits myosin Mg-ATPase activity by modulation of a kinetic step as an integral component of smooth muscle thin filaments

Oldest record of Trimeniaceae from the Early Cretaceous of northern Japan

<p>Abstract</p> <p>Background</p> <p>Molecular phylogenetic analyses have identified Trimeniaceae, a monotypic family distributed only in Oceania, as among the earliest diverging families of extant angiosperms. Therefore, the fossils of this family are helpful to understand the earliest flowering plants. Paleobotanical information is also important to track the historical and geographical pathways to endemism of the Trimeniaceae. However, fossils of the family were previously unknown from the Early Cretaceous, the time when the angiosperm radiated. In this study, we report a seed from the late Albian (ca. 100 million years ago) of Japan representing the oldest known occurrence of Trimeniaceae and discuss the character evolution and biogeography of this family.</p> <p>Results</p> <p>A structurally preserved seed was collected from the early Late Albian Hikagenosawa Formation of the Yezo Group, which was deposited in palaeolatitudes of 35 to 40°N. The seed has a multilayered stony exotesta with alveolate surface, parenchymatous mesotesta, and operculate inner integument, which are characteristic to extant trimeniaceous seeds. However, the seed differs from extant seeds, i.e., in its well-developed endosperm and absence of antiraphal vascular bundle. Thus, the seed would be a new genus and species of Trimeniaceae.</p> <p>Conclusion</p> <p>The fossil seed indicates that seed coat characters were conserved for 100 million years or more in Trimeniaceae. It also suggests that the antiraphal vascular bundle and perispermy originated secondarily in Trimeniaceae as previously inferred from the phylogeny and character distribution in the extant basalmost angiosperms. The fossil seed provides the first evidence that Trimeniaceae was distributed in a midlatitude location of the Northern Hemisphere during the Early Cretaceous, when angiosperms radiated extensively, supporting a hypothesis that the extant austral distribution is relict.</p