Source below the free surface of a heavy liquid

The problem of the motion of a source under the free surface of an infinitely deep heavy liquid has been studied by Keldysh [1] under the assumptions used in the theory of small amplitude waves. However, these assumptions are no longer valid [2] for large Froude numbers F.A method using only one of the four assumptions of small amplitude wave theory (the assumption that the absolute value of the velocity at the free surface is nearly constant) was described in [2], In the following, this method is used to construct a solution of the problem which becomes exact as F . When F is not large our results are close to those of Keldysh if the source intensity is low. For F=0, both methods lead to exact results.     

Large-Scale Streamwise Vortices in the Supersonic Part of a Permeable Nozzle

Large-scale streamwise vortices in the vicinity of a perforated wall in the supersonic part of the nozzle are studied. The governing effect of gas inflow through a perforated wall on origination and parameters of streamwise vortices is experimentally established.__________Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 46, No. 5, pp. 68–75, September–October, 2005.     

p-V-T parameters of propylencarbonate and cis-,trans-decahydronaphthalene in temperature and pressure ranges of 20–50°C and 1–1000 bar

The condensability of propylencarbonate and cis-,trans-decalin (40: 60 wt %) were measured using the liquid weighting method in the temperature and pressure ranges of 20–50°C and 1–1000 bar, respectively. The Tait equation coefficients C and B for this temperature interval were calculated. Taking pro-pylencarbonate as an example, it was demonstrated that equation 1/β _T = 0.9759 × (1000V ₀/ΔV _{1 kbar}) — 4386 proposed earlier for liquids allows us to predict C and B coefficients with good precision.     

Wide-line 1H NMR and DSC study of mesomorphic transformations of p-(alkoxybenzylidene)-p′-toluidines

p-(Alkoxybenzylidene)-p′-toluidines (ABTs) with 7, 8, and 10 carbon atoms in the alkyl moiety have been studied by wide-line ¹H NMR and DSC. The thermotropic properties of these compounds have been studied in the temperature range 20–80°C, including main mesomorphic transformations of ABTs. The 1H NMR line shapes, widths, and second moments, as well as specific features of their temperature-induced changes, are discussed. The DSC data are compared with the character of mesomorphic transformations and ¹H NMR data. The formation limits and ranges and stabilities of liquid-crystalline states of the ABT structure emerging on heating are determined.     

Influence of cholesterol and ceramide VI on the structure of multilamellar lipid membranes at water exchange

The structural changes in the multilamellar lipid membranes of dipalmitoylphosphatidylcholine (DPPC)/cholesterol and DPPC/ceramide VI binary systems during hydration and dehydration have been studied by neutron diffraction. The effect of cholesterol and ceramide on the kinetics of water exchange in DPPC membranes is characterized. Compared to pure DPPC, membranes of binary systems swell faster during hydration (with a characteristic time of ∼30 min). Both compounds, ceramide VI and cholesterol, similarly affect the hydration of DPPC membranes, increasing the repeat distance due to the bilayer growth. However, in contrast to cholesterol, ceramide significantly reduces the thickness of the membrane water layer. The introduction of cholesterol into a DPPC membrane slows down the change in the parameters of the bilayer internal structure during dehydration. In the DPPC/ceramide VI/cholesterol ternary system (with a molar cholesterol concentration of 40%), cholesterol is partially released from the lamellar membrane structure into the crystalline phase.     

Thermodynamic properties of the superconductivity in quasi-two-dimensional Dirac electronic systems

The thermodynamic properties of superconducting Dirac electronic systems is analyzed in the vicinity of quantum critical point. The system is characterized by a quantum critical point at zero doping, such that the critical temperature vanishes below some finite value of interaction strength. It is found that the specific heat jump of the system largely deviates from the conventional BCS theory value in the vicinity of quantum critical point. We investigated the region of applicability of the mean-field theory using the Ginzburg-Landau functional.     

Synthesis and electrochemical properties of lithium-vanadium bronze

Original method for synthesis of a lithium-vanadium bronze was developed. The method includes mechanical activation of a mixture of metavanadic acid and lithium carbonate in the course of a plastic flow under twisting.     

Lifting of dust particles behind a reflected shock wave sliding above a particle layer

The paper presents results of mathematical simulation of particle lifting behind a shock wave reflected from the face wall and sliding above the particle layer. It is shown that particle lifting occurs in a vortex initiated in the gas when the shock wave is reflected from the wall.     

Effect of External Pressure and Solvent on the Equilibrium Constant of the Diels-Alder Reaction of 9-Chloroanthracene with Tetracyanoethylene

The effect of external pressure and solvent on the equilibrium constant of the Diels-Alder reaction of tetracyanoethylene with 9-chloroanthracene at 25°C was studied. The molar reaction volume is strongly solvent-dependent, cm³/mol: -11.3±1.0 in o-xylene, -14.9±1.0 in toluene, -20.6±1.5 in 1,2-dichloroethane, -22.6±1.5 in ethyl acetate, and -24.2±1.5 in acetonitrile.