185 research outputs found
Periodicity and criticality in the Olami-Feder-Christensen model of earthquakes
Characteristic versus critical features of earthquakes are studied on the
basis of the Olami-Feder-Christensen model. It is found that the local
recurrence-time distribution exhibits a sharp -function-like peak
corresponding to rhythmic recurrence of events with a fixed ``period'' uniquely
determined by the transmission parameter of the model, together with a
power-law-like tail corresponding to scale-free recurrence of events. The model
exhibits phenomena closely resembling the asperity known in seismology
Semipolar {n[n¯]01} InGaN/GaN ridge quantum wells (n = 1−3) fabricated by a regrowth technique
Semipolar {n[n¯]01} InGaN/GaN quantum wells (QWs) (n = 1−3) are fabricated on top of GaN microstructures, which consist of semipolar {1Ī01} facets. Semipolar planes are obtained via regrowth of three-dimensional structures on (0001) GaN templates under controlled growth conditions. Compared to QWs on {1Ī01} facets, {n[n¯]01} ridge QWs show an intense emission at ∼ 440 nm. Time resolved photoluminescence reveals that the radiative lifetime of excitons in {n[n¯]01} InGaN ridge QWs at 13 K is 310 ps, which is comparable to that in {1Ī01} QWs. The estimated internal quantum efficiency at room temperature is as high as 57%
Fabrication method of Yb based Oxide matrix for CMC
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Advances and technical challenges in development of CMC
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Asperity characteristics of the Olami-Feder-Christensen model of earthquakes
Properties of the Olami-Feder-Christensen (OFC) model of earthquakes are
studied by numerical simulations. The previous study indicated that the model
exhibits ``asperity''-like phenomena, {\it i.e.}, the same region ruptures many
times near periodically [T.Kotani {\it et al}, Phys. Rev. E {\bf 77}, 010102
(2008)]. Such periodic or characteristic features apparently coexist with
power-law-like critical features, {\it e.g.}, the Gutenberg-Richter law
observed in the size distribution. In order to clarify the origin and the
nature of the asperity-like phenomena, we investigate here the properties of
the OFC model with emphasis on its stress distribution. It is found that the
asperity formation is accompanied by self-organization of the highly
concentrated stress state. Such stress organization naturally provides the
mechanism underlying our observation that a series of asperity events repeat
with a common epicenter site and with a common period solely determined by the
transmission parameter of the model. Asperity events tend to cluster both in
time and in space
Case of 24-week Fetus Delivered from Mother on Life Support with Brain-death from Suicide Attempt: Ethical Issues Associated with Severe Complications
Advances in critical care medicine have made it possible to sustain vital organ systems in brain-dead patients. One clinical scenario besides donor organ retrieval in which a benefit may be gained from continuing life support is pregnancy. A pregnant woman in her late 30ʼs at 23 weeks gestation exhibiting worsening depression was referred to the Department of Psychiatry. One day after admission she attempted suicide by hanging and suffered a cardiopulmonary arrest. A fetal heart beat and fetal motion was confirmed immediately after resuscitation. Three days after admission, an emergency Cesarean section (CS) was performed because of her unstable hemodynamic situation. The baby was born and the mother died after delivery. The baby presented neurological complications. Such a case should be managed collaboratively among professional experts in several medical teams. Consensus and recommendations for the management of similar scenarios may also be adjusted
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