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.
Empirical Determination of Areal Density Capability
A method is presented for determining the practical areal density capability of a magnetoresistive head/disk design from two quick error rate measurements. The method is generally independent of write width and track pitch and facilitates the direct comparison of MR readers or disk media.
Study of External Parasites Infesting Carcharhinus Melanopterus Fish From The Red Sea In Jeddah, Saudi Arabia
Parasitic diseases are harmful and limiting factors in breeding and rearing ornamental fish industry, such as the Monogenea ( Dactylogyrus sp and Erpocotyletiburonis ) and copepod ( Pandarus sinuatus  and Anchistrotostangi ). The copepod and the monogenean are gill parasites found on the shark; CarcharhinusMelanopterus . The primary purpose of this study was to determine the parasitic infections of sharks in red sea in Jeddah. For this purpose, 19 female C. Melanopterus and 14 male C. Melanopterus were first examined for ectoparasites using wet mount under a light microscope. All male sharks had Monogenea and/or copepod in their gill and only 3 females haven’t infections. Then, we aimed to find a combination of copepod and monogenea infection in C. Melanopterus gills. 50% of male and 42% of female were infected by copepod and monogenea. Our findings revealed that the protozoan infections are very common among sharks. Although, no gross pathology was observed among infected shark, but it is likely that in case of any changes in the environment, then parasitic infections could be harmful.