Transport coefficients in a dilute but condensed Bose gas

The kinetic equations for a dilute superfluid developed previously are used to derive the Landau-Khalatnikov two-fluid hydrodynamic equations. Explicit expressions for the associated transport coefficients are given for very low temperatures and for moderately low temperatures.     

Properties and Performance of High-Purity Thermal Barrier Coatings

It has been found that reducing the level of impurity oxides (particularly SiO₂ and Al₂O₃) in 7YSZ, from about 0.2 wt% to below 0.1 wt% raises the sintering resistance and the phase stability of plasma-sprayed coatings. The implications for the usage of these coatings at elevated temperatures are examined. It is concluded that using relatively high-purity powder of this type is likely to confer substantial benefits in terms of the thermomechanical stability of the coatings under service conditions. This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain Montavon, Ed., ASM International, Materials Park, OH, 2007.     

Boundary layer of non-Newtonian fluids obeying a rheological power law for arbitrary pressure gradients

The equations of the boundary layer associated with non-Newtonian fluids obeying a rheological power law are integrated by a semiintegral method based on the simultaneous solution of the linearized equation of motion and the integral relationship.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 20, No. 3, pp. 398–404, March, 1971.     

Quantitative microfluidic separation of DNA in self-assembled magnetic matrixes

We present an experimental study of the microfluidic electrophoresis of long DNA in self-assembling matrixes of magnetic bead columns. Results are presented for the rapid separation of lambda-phage, 2lambda-DNA, and bacteriophage T4 DNA, where separation resolutions greater than 2 between lambda and T4 are achieved in times as short as 150 s. The use of a computer-piloted flow control system and injection results in high reproducibility between separations. We compare the experimentally measured mobility and dispersion with an exactly solvable lattice Monte Carlo model. The theory predicts that the mean velocity scales linearly with the field, the band broadening scales with the inverse of the field, and the resolution is independent of the field for intermediate fields-all of which are in accord with the experimental results. Moreover, reasonable quantitative agreement is achieved for band broadening for longer DNA (2lambda and T4) when the average postengagement time is measured experimentally. This work demonstrates the possibility of achieving fast microfluidic separation of large DNA on a routine basis.     

Numerical analysis of the development of a system of jets in the region of mixing of oppositely twisted annular flows

Results are presented from a study of the flow structure and mass transfer in a combustion chamber employing the microflame diffusion principle of combustion in a twisted flow. The study was conducted with an isothermal computational model.     

Plasma modification of a protective coating formed by hexamethyleniminem-nitrobenzoate on iron

A layer of hexamethyleniminem-nitrobenzoate was modified in low-temperature plasma on the air-oxidized iron surface. The composition and physicochemical properties of the modified inhibitor was studied by XPES and atomic force microscopy. It was assumed and then justified that the enhanced protective properties of a plasma-treated coating are due to the formation of corrosion-resistant iron nitrides and oxides, as well as new nitrogen- and oxygen-containing organic compounds with better inhibitive and adhesive abilities. Plasma-induced polymerization of the coating results in a high-strength, dense hydrophobic film that seems to be responsible for its enhanced barrier properties.     

Time correlation functions and transport coefficients in a dilute superfluid

Time correlation functions for the transport coefficients in the linear Landau-Khalatnikov equations are derived on the basis of a formal theory. These Green-Kubo expressions are then explicitly evaluated for a dilute superfluid and the resulting transport coefficients are shown to be identical to those obtained previously by using a distribution function method.