THE INFLUENCE OF EXTERNAL FLOW ON THE DYNAMIC OF ARC CHANNEL MOVING ALONG THE WALL WITHIN A MAGNETIC FIELD

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Characterization of Cholinesterases in Plasma of Three Portuguese Native Bird Species: Application to Biomonitoring

Over the last decades the inhibition of plasma cholinesterase (ChE) activity has been widely used as a biomarker to diagnose organophosphate and carbamate exposure. Plasma ChE activity is a useful and non-invasive method to monitor bird exposure to anticholinesterase compounds; nonetheless several studies had shown that the ChE form(s) present in avian plasma may vary greatly among species. In order to support further biomonitoring studies and provide reference data for wildlife risk-assessment, plasma cholinesterase of the northern gannet (Morus bassanus), the white stork (Ciconia ciconia) and the grey heron (Ardea cinerea) were characterized using three substrates (acetylthiocholine iodide, propionylthiocholine iodide, and S-butyrylthiocholine iodide) and three ChE inhibitors (eserine sulphate, BW284C51, and iso-OMPA). Additionally, the range of ChE activity that may be considered as basal levels for non-exposed individuals was determined. The results suggest that in the plasma of the three species studied the main cholinesterase form present is butyrylcholinesterase (BChE). Plasma BChE activity in non-exposed individuals was 0.48±0.11 SD U/ml, 0.39±0.12 SD U/ml, 0.15±0.04 SD U/ml in the northern gannet, white stork and grey heron, respectively. These results are crucial for the further use of plasma BChE activity in these bird species as a contamination bioindicator of anti-cholinesterase agents in both wetland and marine environments. Our findings also underscore the importance of plasma ChE characterization before its use as a biomarker in biomonitoring studies with birds

Comparison of mantle lithosphere beneath early Triassic kimberlite fields in Siberian craton reconstructed from deep-seated xenocrysts

Mantle xenocrysts from Early Triassic kimberlite pipes from Kharamai, Ary Mastakh and Kuranakh fields in the Anabar shield of Siberia revealing similar compositional trends were studied to estimate the superplume influence on the SCLM. PT reconstructions using monomineral thermobarometry for 5 phases show division of the SCLM beneath the Kharamai field into 6 units: pyroxenitic Fe-rich (1-2 GPa) and Mg-rich (2-3 GPa) layers; middle with two levels of Gar -Sp pyroxenites at ∼3 and 4 -5 GPa; Ga- dunite –harzburgites ∼ 4.5-6.5 GPa subjected to Ilm-Px vein metasomatism, and a Mg-rich dunite lower part. In the Anabar shield (Ary Mastakh, Dyuken and Kuranakh fields) mantle lithosphere is composed of three large units divided into two parts: upper part with amphiboles and phlogopite; two levels of pyroxenites and eclogites at 3 and 4 GPa, and a lower part composed of refertilized dunites. Diagrams showing P- Fe#Gar clusters for garnets and omphacites illustrate the differences between SCLM of these localities. Differences of Triassic SCLM from Devonian SCLM are in simple layering; abundance of Na-Cr-amphiboles and metasomatism in the upper SCLM part, thick pyroxenite - eclogite layer and lower part depletion, heated from SCLM base to 5.0 GPa. Kharamai mantle clinopyroxenes represent three geochemical types: 1) harzburgitic with inclined linear REE, HFSE troughs and elevated Th, U; 2) lherzolitic or pyroxenitic with round TRE patterns and decreasing incompatible elements; 3) eclogitic with Eu troughs, Pb peak and high LILE content. Calculated parental melts for garnets with humped REE patterns suggest dissolution of former Cpx and depression means Cpx and garnets extraction. Clinopyroxenes from Ary Mastakh fields show less inclined REE patterns with HMREE troughs and an increase of incompatible elements. Clinopyroxenes from Kuranakh field show flatter spoon-like REE patterns and peaks in Ba, U, Pb and Sr, similar to those in ophiolitic harzburgites. The PT diagrams for the mantle sections show high temperature gradients in the uppermost SCLM accompanied by an increase of P-Fe#Ol upward and slightly reduced thickness of the mantle keel of the Siberian craton, resulting from the influence of the Permian -Triassic superplume, but with no signs of delamination

Turbulent Boundary Layer Separation Control Using Magnetohydrodynamic Plasma Actuator

The pulse electric arc discharge in an external magnetic field is studied as a vortex generator in the subsonic boundary layer. A pulsed Ampere force induces a hairpin vortex near the wall; its structure depends on the relative direction of arc propagation and external flow velocity. The data presented in this article were obtained from parametric studies of vortex characteristics and their effects on the boundary layer profile at various actuator momentum coefficients (Cμ=1−30) and vortex sizes relative to the boundary layer thickness (D/δ=0.5−1.2). Also, the control of turbulent boundary layer separation on a bump at a flow velocity up to 50 m/s was attempted. An average shift of the separation line by 15% of the bump height was obtained at a flow velocity of 50 m/s and a total momentum coefficient of 0.6%

The effect of the exposed electrode oxidation on the filamentation thresholds of a nanosecond DBD

International audienc

THE INFLUENCE OF EXTERNAL FLOW ON THE DYNAMIC OF ARC CHANNEL MOVING ALONG THE WALL WITHIN A MAGNETIC FIELD

-58-5