Quantifying oil filtration effects on bearing life

Rolling-element bearing life is influenced by the number, size, and material properties of particles entering the Hertzian contact of the rolling element and raceway. In general, rolling-element bearing life increases with increasing level of oil filtration. Based upon test results, two equations are presented which allow for the adjustment of bearing L(sub 10) or catalog life based upon oil filter rating. It is recommended that where no oil filtration is used catalog life be reduced by 50 percent

Electronic Structure of Superconducting Ba6c60

We report the results of first-principles electronic-structure calculations for superconducting Ba6C60. Unlike the A3C60 superconductors, this new compound shows strong Ba-C hybridization in the valence and conduction regions, mixed covalent/ionic bonding character, partial charge transfer, and insulating zero-gap band structure.Comment: 11 pages + 4 figures (1 appended, others on request), LaTeX with REVTE

The Riccati System and a Diffusion-Type Equation

We discuss a method of constructing solution of the initial value problem for duffusion-type equations in terms of solutions of certain Riccati and Ermakov-type systems. A nonautonomous Burgers-type equation is also considered.Comment: 11 pages, no figure

Instability of spatial patterns and its ambiguous impact on species diversity

Self-arrangement of individuals into spatial patterns often accompanies and promotes species diversity in ecological systems. Here, we investigate pattern formation arising from cyclic dominance of three species, operating near a bifurcation point. In its vicinity, an Eckhaus instability occurs, leading to convectively unstable "blurred" patterns. At the bifurcation point, stochastic effects dominate and induce counterintuitive effects on diversity: Large patterns, emerging for medium values of individuals' mobility, lead to rapid species extinction, while small patterns (low mobility) promote diversity, and high mobilities render spatial structures irrelevant. We provide a quantitative analysis of these phenomena, employing a complex Ginzburg-Landau equation.Comment: 4 pages, 3 figures and supplementary information. To appear in Phys. Rev. Lett

Three-dimensional electronic instabilities in polymerized solid A1C60

The low-temperature structure of A1C60 (A=K, Rb) is an ordered array of polymerized C60 chains, with magnetic properties that suggest a non-metallic ground state. We study the paramagnetic state of this phase using first-principles electronic-structure methods, and examine the magnetic fluctuations around this state using a model Hamiltonian. The electronic and magnetic properties of even this polymerized phase remain strongly three dimensional, and the magnetic fluctuations favor an unusual three-dimensional antiferromagnetically ordered structure with a semi-metallic electronic spectrum.Comment: REVTeX 3.0, 10 pages, 4 figures available on request from [email protected]