Areal-Density Capability Measurement Based on 747 Test in Magnetic Recording Systems
A method is presented for determining the areal density (AD) capability of a magnetic recording system based on a set of 747 tests taken over a range of linear densities. By fitting the measured results with a suitable functional form, we can readily predict off-track capability (OTC) at any combination of linear density and track density. Conversely, for a given OTC requirement, we can immediately find the maximum AD that can be reached and the bit aspect ratio required to achieve it. Our results also reveal the effect of skew angle on AD and match well with previous results for perpendicular magnetic recording.
Modeling of 747 Curves in Magnetic Recording Systems
In this article, we discuss the models of the 747 test, in particular, the 747 test taken over a range of linear densities. In a comparison study, we fit the 747 curves at three conditions, as well as different upper limits of the track pitch. Based on the comparison result, we present a general model for the 747 curves as a function of linear density. The new proposed model not only improves the accuracy but also extends the applicable scope of the fitting. With the model, we also demonstrate the optimal combinations of track density and linear density for maximizing the off-track-capability (OTC) and squeeze-to-death (S2D), as well as their maximums as a function of areal density.
Benign approaches for the synthesis of bis-imine Schiff bases
Pure bis-imine Schiff bases are readily accessible in high yield, typically >95%, when aliphatic diamine/aldehyde condensation reactions are carried out under solvent-free conditions or in poly(propyleneglycol) (PPG) as a recyclable reaction medium, with negligible waste.