Abstract: A data storage device is disclosed comprising a head actuated over a disk. A test pattern is read from a first part of the disk to generate a first read signal that is sampled to generate a first sequence of signal samples. The test pattern is read from a second part of the disk to generate a second read signal that is sampled to generate a second sequence of signal samples. A third sequence of signal samples is generated by at least one of amplitude-inverting the second sequence of signal samples, time-inverting the second sequence of signal samples, and amplitude-inverting and time-inverting the second sequence of signal samples. A quality metric is generated based on the first sequence of signal samples and the third sequence of signal samples, and a data density of the disk is configured based on the quality metric.

Abstract: A data storage device is disclosed comprising a head actuated over a disk. A test pattern is read from a first part of the disk to generate a first read signal that is sampled to generate a first sequence of signal samples. The test pattern is read from a second part of the disk to generate a second read signal that is sampled to generate a second sequence of signal samples. A third sequence of signal samples is generated by at least one of amplitude-inverting the second sequence of signal samples, time-inverting the second sequence of signal samples, and amplitude-inverting and time-inverting the second sequence of signal samples. A quality metric is generated based on the first sequence of signal samples and the third sequence of signal samples, and a data density of the disk is configured based on the quality metric.

Abstract: A data storage device is disclosed comprising a disk comprising a plurality of data tracks, wherein each data track comprises a plurality of data sectors, each data sector comprises a preamble, and the preambles of adjacent data tracks are recorded at different frequencies. A first read element and a second read element of a head are positioned over a first preamble of a first data track to generate a first read signal emanating from the first read element and a second read signal emanating from the second read element. A first metric is generated based on the first read signal and a second metric is generated based on the second read signal. A difference between the first metric and the second metric is generated and used, for example, to servo the head over the disk or to measure a radial offset between the read elements.

Abstract: A method, apparatus, and system are provided for implementing track following using signal asymmetry metrics monitored during read back in hard disk drives (HDDs). Signal asymmetry metrics monitored during read back are used together with a position error signal (PES) to correct and guide the position of a read sensor with respect to a written track in the HDD.

Abstract: A method, apparatus, and system are provided for implementing track following using signal asymmetry metrics monitored during read back in hard disk drives (HDDs). Signal asymmetry metrics monitored during read back are used together with a position error signal (PES) to correct and guide the position of a read sensor with respect to a written track in the HDD.

Abstract: An insert assembly (fitment) includes a container mounting element, a spout element carried by the mounting element, at least one support element and a grasp element suspended by the support element(s) below the mounting element. The grasp element provides a skeleton within a pouch-type flexible container, against which a user can grasp and squeeze the flexible container for mixing or drinking Optionally or alternatively, a mixing element is suspended by the support element(s). The mixing element impinge upon at least a portion of fluid within the container to create turbulence, thereby promoting mixing of powdered material disposed within the container.

Abstract: Methods for measuring media performance associated with adjacent track interference are provided. One such method includes iteratively writing data to a target track for each of a plurality of n frequencies, measuring a first signal amplitude and a first noise for each of the n sectors on the target track, writing an aggressor track pattern proximate the target track, measuring a second signal amplitude and a second noise for each of the n sectors on the target track, calculating a weighted sum for each of the signal amplitude measurements for each of the plurality of n frequencies, and calculating a weighted sum for each of the noise measurements for each of the plurality of n frequencies, and repeating the writing the aggressor track pattern, the measuring the second signal amplitude and the second noise, and calculating the weighted sums for preselected numbers of times.

Abstract: An insert assembly (fitment) includes a container mounting element, a spout element carried by the mounting element, at least one support element and a grasp element suspended by the support element(s) below the mounting element. The grasp element provides a skeleton within a pouch-type flexible container, against which a user can grasp and squeeze the flexible container for mixing or drinking Optionally or alternatively, a mixing element is suspended by the support element(s). The mixing element impinge upon at least a portion of fluid within the container to create turbulence, thereby promoting mixing of powdered material disposed within the container.

Abstract: Methods for measuring media performance associated with adjacent track interference are provided. One such method includes iteratively writing data to a target track for each of a plurality of n frequencies, measuring a first signal amplitude and a first noise for each of the n sectors on the target track, writing an aggressor track pattern proximate the target track, measuring a second signal amplitude and a second noise for each of the n sectors on the target track, calculating a weighted sum for each of the signal amplitude measurements for each of the plurality of n frequencies, and calculating a weighted sum for each of the noise measurements for each of the plurality of n frequencies, and repeating the writing the aggressor track pattern, the measuring the second signal amplitude and the second noise, and calculating the weighted sums for preselected numbers of times.

Abstract: Cross-track density capability is predicted for a large number of writes based on a plurality of erase band width measurements. Over the plurality of erase band width measurements, a number of writes in a series of writes performed as part of an aggressing track sequence is varied. A model of the magnetic track width (MTW) as function of the number of writes employed in the MTW measurements may be generated and an estimate of the erase band width for a large number of writes derived from the model as a prediction of cross-track density capability.

Abstract: A wide area track erasure (WATER) rate of change is determined from a model generated from a plurality of track erasure measurements performed on a magnetic recording media. A model of the change in noise amplitude for an off-track position as a function of the number of aggressor track writes employed in the track erasure measurements is generated. In a log-linear space a linear fit of the change in noise amplitude with respect to the number of aggressor track writes yields a rate of noise amplitude change (dB/decade) which may be utilized to rank magnetic recording media.