4,235 research outputs found
Late Silurian trace fossils from the Melbourne Formation, Studley Park, Victoria, southeastern Australia
An ichnoassemblage of 10 ichnospecies is described for the first time from the Late Silurian Melbourne Formation at Studley Park, Victoria, southeastern Australia. The ichnofauna is preserved in a typical deep-water turbidite succession of alternating thin- to thick-bedded sandstone and thin- to medium-bedded mudrocks. Trace fossils observed within the study site have been assigned to three main ichnofacies. Ichnofacies 1 is best developed on the linguoid-rippled upper surface of thin sandstone beds and includes Laevicyclus, Aulichnites, Nereites, Helminthoidichnites, small Chondrites and possible Zoophycos. Ichnofacies 2 is very similar to Ichnofacies 1 in ichnospecies composition but instead contains large forms of Chondrites together with other thin burrow types usually poorly preserved and in very low abundance compared with Ichnofacies 1. Ichnofacies 3 is preserved mainly as casts on the underside of medium- to thick-bedded turbiditic sandstones, and has a very low diversity, with Planolites being the most common trace. A detailed analysis of the ichnofabrics and tiering structures of these ichnofacies suggest that Ichnofacies 1 and 3 represent "simple tiering’, in contrast to Ichnofacies 2, which is more characteristic of \u27complex tiering’. Despite the differences in ichnospecies composition and ichnofabrics between the three recognized ichnofacies, the collective ichnoassemblage from the study site can be assigned confidently to the Nereites ichnofacies and is, therefore, interpreted to have formed in a distal submarine fan environment of lower bathyal to abyssal depth. Further, it is possible to recognize two main subenvironments within this deep-sea setting to account for the differences between the ichnofacies. Ichnofacies 1 and 2 are interpreted to represent a typical Nereites ichnofacies located on a level basin floor subenvironment of relatively low energy conditions at the distal end of a submarine fan deposit. In comparison, Ichnofacies 3 is dominated by Planolites with rare other facies-crossing trace fossil forms, and lacks Nereites. It is, therefore, best interpreted as representing a relatively high-energy environment, possibly a distributary channel near the distal end of the submarine fan system.<br /
Effects of polymer additives in the bulk of turbulent thermal convection
We present experimental evidence that a minute amount of polymer additives
can significantly enhance heat transport in the bulk region of turbulent
thermal convection. The effects of polymer additives are found to be the
\textit{suppression} of turbulent background fluctuations that give rise to
incoherent heat fluxes that make no net contribution to heat transport, and at
the same time to \textit{increase} the coherency of temperature and velocity
fields. The suppression of small-scale turbulent fluctuations leads to more
coherent thermal plumes that result in the heat transport enhancement. The fact
that polymer additives can increase the coherency of thermal plumes is
supported by the measurements of a number of local quantities, such as the
extracted plume amplitude and width, the velocity autocorrelation functions and
the velocity-temperature cross-correlation coefficient. The results from local
measurements also suggest the existence of a threshold value for the polymer
concentration, only above which can significant modification of the plume
coherent properties and enhancement of the local heat flux be observed.
Estimation of the plume emission rate suggests that the second effect of
polymer additives is to stabilize the thermal boundary layers.Comment: 8 figures, 11 page
Surgical Management of Traumatic Facial Paralysis: A Case Review Study
AbstractObjectiveTo evaluate efficacy of surgical treatment in traumatic facial paralysis.MethodsThirty–three cases were reviewed, including temporal bone fracture and iatrogenic facial nerve injury. All the patients were treated with various surgical methods according to their pathogeny.ResultsThe mean percentage facial function improvement (House–Brackmann Grade I – II) was 86% in temporal bone fracture and function was improved after proper operation to iatrogenic facial nerve injury.ConclusionsPatients with traumatic facial paralysis receive proved outcomes itreaed with proper surgical methods according to their particular condition of nerve injury
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