Wear properties of perpendicular magnetic recording media

Wear properties of sputtered Co-Cr/permalloy double layer on flexible substrate with and without an inorganic protective top layer were studied under simulated tribological conditions. A soft head slider (ex. glass) gave even severer damage to media than the hard one (ex. Al2O3-TiC), and a 200 Å thin inorganic protective top layer was effective enough to enhance resistance against wear. Read-write experiments were also done with use of the double layer flexible media with the protective top layer (200 Å in thickness) by running them on a specially designed driver unit with an Al2O3.TiC spherical SPT head. An out-put signal loss was no more than 3dB even after 10 million times of the head passes.     

Continuous measurements of bronchial exposure induced by radon decay products during inhalation

The deposition of radon decay products is not equal in each of the respiratory regions and as the presence of radon has been linked with an increase in lung cancer risk, it is important to calculate the deposition of radon decay products in each of the respiratory regions. Recently, many studies on the deposition of radon in respiratory regions have been simulated using wire screens. The systems and equipment used in those studies are not suitable for field measurements as their dimensions are relatively massive, nor can they measure continuously. We developed a continuous bronchial dosimeter (CBD) which is suitable for field measurements. It was designed with specifications that allow it to be remain compact. The CBD simulates the deposition of radon decay products in the different respiratory regions by the use of a combination of wire screens. Deposition in the simulated regions of the lung can be continuously estimated in various environments. The ratio of activities deposited in a simulated nasal cavity (N) and tracheobronchial (TB) regions was calculated from the results of simultaneous measurements using CBD-R (reference), CBD-N (nasal), and CBD-TB (tracheobronchial) measurement units. After aerosols were injected into the radon chamber, the ratio of N and TB depositions decreased. This results indicate that the CBD gave a good response to changes in the environment. It was found that the ratio of N and TB deposition also varied with time in each actual environment.     

Thermal post-buckling of circular plates

The thermal post-buckling behaviour of isotropic circular plates has been studied in this paper through a simple finite element formulation. The accuracy of the solution by finite element method is established through a solution by Rayleigh-Ritz method for simply-supported circular plates. Effect of non-linearity on the load parameter is found to be much higher in the case of thermal loading than in the case of mechanical loading.     

Non-linear bending of antisymmetric cross-ply plates

The bending of antisymmetric cross-ply plates, based on Von-Karman plate theory, is investigated in this paper with one term approximations for the in-plane and transverse displacements. Rayleigh-Ritz solutions are presented for the non-linear response of cross-ply laminates with various modular and aspect ratios and subjected to sinusoidal transverse loading.     

Post-traumatic middle cerebral artery occlusion: case report and review

Occlusion of extracranial carotid and vertebral arteries following closed craniocervical trauma is well known. However occlusion of intracranial arteries following closed head injuries is infrequently reported. In fact only 25 cases of post-traumatic middle cerebral artery occlusion have been adequately documented. This entity bears re-emphasis not only because of its rarity but also because of its clinical similarity to other intracranial mass lesions.