776 research outputs found
Virial expansions and augmented van der Waals approach: Application to Lennard-Jones-like Yukawa fluid
We argue that recently proposed [Melnyk et al., Fluid Phase Equilibr., 2009,
Vol. 279, 1] a criterion to split the pair interaction energy into two parts,
one of which is forced to be responsible the most accurate as possible for
excluded volume energy in the system, results in expressions for the virial
coefficients that improve the performance of the virial equation of state in
general, and at subcritical temperatures, in particular. As an example,
application to the Lennard-Jones-like hard-core attractive Yukawa fluid is
discussed.Comment: 12 pages, 6 figure
Development of impact resistant boron/aluminum composites for turbojet engine fan blades
Composite fabrication was performed by vacuum press diffusion bonding by both the foil-filament array and preconsolidated monotape methods. The effect of matrix material, fiber diameter, matrix enhancement, fiber volume reinforcement, test temperature, angle-plying, notch, impact orientation, processing variables and fabrication methods on tensile strength and Charpy impact resistance are evaluated. Root attachment concepts, were evaluated by room and elevated temperature tensile testing, as well as by pendulum-Izod and ballistic impact testing. Composite resistance to foreign object damage was also evaluated by ballistic impacting of panels using projectiles of gelatin, RTV rubber and steel at various velocities, and impingement angles. A significant improvement in the pendulum impact resistance of B-Al composites was achieved
Mean spherical approximation for the Lennard-Jones-like two Yukawa model: Comparison against Monte Carlo data
Monte Carlo simulation studies are performed for the Lennard-Jones like two
Yukawa (LJ2Y) potential to show how properties of this model fluid depend on
the replacement of the soft repulsion by the hard-core repulsion. Different
distances for the positioning of hard core have been explored. We have found,
that for temperatures that are slightly lower and slightly higher of the
critical point temperature for the Lennard-Jones fluid, placing the hard core
at distances that are shorter than zero-potential energy is well justified by
thermodynamic properties that are practically the same as in original LJ2Y
model without hard core. However, going to extreme conditions with the high
temperature one should be careful since presence of the hard core provokes
changes in the properties of the system. The later is extremely important when
the mean spherical approximation (MSA) theory is applied to treat the
Lennard-Jones-like fluid.Comment: 11 pages, 13 figure
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