3,511 research outputs found
Local log-law of the wall: numerical evidences and reasons
Numerical studies performed with a primitive equation model on
two-dimensional sinusoidal hills show that the local velocity profiles behave
logarithmically to a very good approximation, from a distance from the surface
of the order of the maximum hill height almost up to the top of the boundary
layer. This behavior is well known for flows above homogeneous and flat
topographies (``law-of-the-wall'') and, more recently, investigated with
respect to the large-scale (``asymptotic'') averaged flows above complex
topography. Furthermore, this new-found local generalized law-of-the-wall
involves effective parameters showing a smooth dependence on the position along
the underlying topography. This dependence is similar to the topography itself,
while this property does not absolutely hold for the underlying flow, nearest
to the hill surface.Comment: 9 pages, Latex, 2 figure
PROMON: a profile monitor of software applications
Software techniques can be efficiently used to increase the dependability of safety-critical applications. Many approaches are based on information redundancy to prevent data and code corruption during the software execution. This paper presents PROMON, a C++ library that exploits a new methodology based on the concept of "Programming by Contract" to detect system malfunctions. Resorting to assertions, pre- and post-conditions, and marginal programmer interventions, PROMON-based applications can reach high level of dependabilit
Epirubicin. A new entry in the list of fetal cardiotoxic drugs? Intrauterine death of one fetus in a twin pregnancy. Case report and review of literature
BACKGROUND: Current knowledge indicate that epirubicin administration in late
pregnancy is almost devoid of any fetal cardiotoxicity. We report a twin
pregnancy complicated by breast cancer in which epirubicin administration was
causatively linked to the death of one twin who was small for gestational age
(SGA) and in a condition of oligohydramnios and determined the onset of a
transient cardiotoxicity of the surviving fetus/newborn.
CASE PRESENTATION: A 38-year-old caucasic woman with a dichorionic twin pregnancy
was referred to our center at 20 and 1/7 weeks for a suspected breast cancer,
later confirmed by the histopathology report. At 31 and 3/7 weeks, after the
second chemotherapy cycle, ultrasound examination evidenced the demise of one
twin while cardiac examination revealed a monophasic diastolic ventricular
filling, i.e. a diastolic dysfunction of the surviving fetus who was delivered
the following day due to the occurrence of grade II placental abruption. The role
of epirubicin cardiotoxicity in the death of the first twin was supported by
post-mortem cardiac and placental examination and by the absence of structural or
genomic abnormalities that may indicate an alternative etiology of fetal demise.
The occurrence of epirubicin cardiotoxicity in the surviving newborn was
confirmed by the report of high levels of troponin and transient left ventricular
septal hypokinesia.
CONCLUSION: Based on our findings we suggest that epirubicin administration in
pregnancy should be preceded by the screening of some fetal conditions like SGA
and oligohydramnios that may increase its cardiotoxicity and that, during
treatment, the diastolic function of the fetal right ventricle should be
specifically monitored by a pediatric cardiologist; also, epirubicin and
desamethasone for lung maturation should not be closely administered since
placental effects of glucocorticoids may increase epirubicin toxicity
PI controller design of a wind turbine: evaluation of the pole-placement method and tuning using constrained optimization
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