Acoustic streaming with resonance gas oscillations in a cylindrical tube

Acoustic streaming accompanying acoustic resonance oscillations of gas in a tube is considered. The effect of both the Prandtl number and the wall loss on the velocity of acoustic streaming in a viscous heat-conducting medium is investigated. Expressions for the longitudinal and transverse components of the flow velocity are obtained. © 2001 MAIK "Nauka/Interperiodica"

Secondary streaming accompanying the wave propagation in narrow pipes

A theory describing the secondary streaming that accompanies the acoustic wave propagation in a narrow cylindrical pipe of infinite length is presented. © 2003 MAIK "Nauka/Interperiodica"

Experimental approaches to the assessment of potential cardioprotective means with doxorubicin-associated cardiomyopathy

Development of methodological approaches for evaluation of cardioprotective activity of drugs in doxorubicin cardiomyopath

Study of dose-dependent effect of 2-ethyl-6-methyl-3 hydroxypyridine succinate on the contractile function of isolated rat heat

In experiments on the isolated rat heart there were studied the effects of different doses (21.43 mg/kg/day and 85 . 72 mg/kg/day) 2-ethyl-6-methyl-3 hydroxypy ridine succinate ("EkoPharmInvest", Russia), on the contractile function of isolated hearts subjected to prior doxorubicin model (20 mg/kg, intraperitoneal) of pathology. The dynamic of the power mechanisms of ion transport was evaluated by imposing high h eart rate (480 BPM) and increase concentration of Са2+ to 5 mmol in perfusat

Evaluation of cardioprotective effects of the incritinmimetics exenatideand vildagliptin in the experiment

The results of experimental and clinical trials make it clear that incretin mimetics possess pleiotropic effects and demonstrate the value in terms of assessment of their potential opportunities as cardioprotectors. Goals: To study the cardioprotective effects of exenatide and vildagliptin on the model of doxorubicin-induced cardiomyopath

Model of turbulent oscillating flows in smooth tubes

Turbulent oscillating flows in smooth tubes are considered. A group of flows in which the logarithmic boundary layer grows monotonically with time is distinguished; the conditions of quasistationarity of these flows are determined. A model of a quasistationary turbulent oscillating flow in a smooth tube is constructed; the model is in satisfactory agreement with experiment

On the Degradation of Retained Austenite in Transformation Induced Plasticity Steel

© 2020, The Minerals, Metals & Materials Society and ASM International. A transformation-induced plasticity steel was thermomechanically processed and then transformed to bainite at an isothermal transformation temperature of 723 K for 1800 seconds, which exceeds the time required for completion of the bainite transformation. The formation of lenticular-shaped carbides with a triclinic lattice and internal substructure was found after thermomechanical processing. After 16 years of storage at room temperature, the decomposition of retained austenite into pearlite was observed for the first time at this temperature

Strengthening mechanisms in thermomechanically processed NbTi-microalloyed steel

The effect of deformation temperature on microstructure and mechanical properties was investigated for thermomechanically processed NbTi-microalloyed steel with ferrite-pearlite microstructure. With a decrease in the finish deformation temperature at 1348 K to 1098 K (1075 °C to 825 °C) temperature range, the ambient temperature yield stress did not vary significantly, work hardening rate decreased, ultimate tensile strength decreased, and elongation to failure increased. These variations in mechanical properties were correlated to the variations in microstructural parameters (such as ferrite grain size, solid solution concentrations, precipitate number density and dislocation density). Calculations based on the measured microstructural parameters suggested the grain refinement, solid solution strengthening, precipitation strengthening, and work hardening contributed up to 32 pct, up to 48 pct, up to 25 pct, and less than 3 pct to the yield stress, respectively. With a decrease in the finish deformation temperature, both the grain size strengthening and solid solution strengthening increased, the precipitation strengthening decreased, and the work hardening contribution did not vary significantly

A new XRD method to quantify plate and lath martensites of hardened medium-carbon steel

This paper introduces a new technique to separately measure the volume fraction and tetragonal ratio of co-existing lath and plate martensites in ultrahigh strength steel, and to calculate their different carbon contents. First of all, the two martensites are assumed to have body centre tetragonal lattice structures of different tetragonal ratios. X-ray diffraction is then applied to obtain the overlapping (200) diffraction peak, which is subsequently separated as four sub-peaks using a self-made multiple Gaussian peak-fitting method to allow the measurement of the individual lattice parameters c and a. Finally a modified equation is applied to calculate the carbon contents from the obtained tetragonal ratios. The new technique is then applied to investigate the effect of subsequent tempering on the decarbonisation of the as-quenched martensites. Keywords: Gaussian peak-fitting, martensite carbon content, martensite tetragonal ratio, medium-carbon steels, Xray diffractio