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The migration process of contamination materials in the porous rock mass was visualized and analyzed by X-ray CT image data. In this study, Kimachi sandstone, which had approximately 26% porosity, was used as a rock sample. Here two cases of diffusion phenomena were analyzed. One is the case that solute diffuses into the porous rock mass from the crack surfaces, and it simulates the contamination process of rock mass. Another is the case that the solute diffuses out of the porous rock mass, and it simulates the process that the contamination materials spread from highly contaminated sources. It was found that the diffusion phenomena were clearly visualized by X-ray CT method. By introducing the parameter, coefficient of tracer density increment α, quantitative analysis of tracer density became possible, and the relation between the density distribution of tracer and the crack apertures and the relation between the density distribution and porosity distribution became clear.
We review on Zariski 3-algebra model of M-theory. The model is obtained by Zariski quantization of a semi-light-cone supermembrane action. The model has manifest N=1 supersymmetry in eleven dimensions and its relation to the supermembrane action is clear.
are concerned as a major cause of postoperative respiratory depression. In the
immediate postoperative period, however, other factors can produce instability
of breathing such as pain, agitation, and residual effects of anesthetics. Such
factors might be overlooked masked by the fear for opioid-induced respiratory
depression. We report a case who presented apnea immediately after emergence
from anesthesia that we considered was produced by an interaction among such
factors accompanied with fentanyl-induced respiratory depression. Clinical Features:
A 31-year-old woman underwent ovarian cystectomy under general anesthesia with
continuous infusions of propofol and remifentanil, and bolus doses of fentanyl.
Transversus abdominis plane blocks with ropivacaine were given upon completion
of surgery. She complained of severe wound pain and was agitated at the
emergence from anesthesia. Fentanyl 50 μg was administered intravenously. In
several minutes, she developed apnea, unconsciousness, and difficulty of
mechanical ventilation via a face mask. The estimated effect site concentration
at the onset of the episode (2.9 ng·ml-1)
was approximately the same (3.0 ng·ml-1)
as after 30 min when she regained consciousness and spontaneous breathing. It
indicated that not only direct inhibition of the respiratory center by fentanyl
but also other stimulatory and inhibitory factors contributed to respiratory arrest.
Conclusion: In the immediate postoperative period, transient factors, such as
pain, mental instability
discusses the question of how elasticity of the system is intertwined with
external stochastic disturbances. The speed at which a displaced system returns
to its equilibrium is a measure of density dependence in population dynamics.
Population dynamics in random environments, linearized around the equilibrium
point, can be represented by a Langevin equation, where populations fluctuate
under locally stable (not periodic or chaotic) dynamics. I consider a Langevin
model in discrete time, driven by time-correlated random forces, and examine
uncertainty in locating the population equilibrium. There exists a time scale
such that for times shorter than this scale the dynamics can be approximately
described by a random walk; it is difficult to know whether the system is
heading toward the equilibrium point. Density dependence is a concept that
emerges from a proper coarse-graining procedure applied for time-series
analysis of population data. The analysis is illustrated using time-series data
from fisheries in the North Atlantic, where fish populations are buffeted by
stochastic harvesting in a random environment.