Study on process and performance of laser heating assisted micro cutting of alumina ceramics
For the study of alumina ceramic micro turning machining performance, using (IPGPhotonis) fiber laser heating assisted cutting. Due to the high strength and hardness of the alumina ceramics, using cubic boron nitride (CBN) tool for turning experiment. The effects of different processing parameters such as laser power, spindle speed and feed rate on the surface roughness and tool wear were studied. Compared with the experimental results obtained by laser heating and non-laser heating, we found that the surface quality is improved by laser heating, and the service life of the cutter is prolonged.
Laser Assisted Machining: An Overview
Since laser technology has considerable synergy with machining technologies, Laser Machining (LM) and Laser Assisted Machining (LAM) are relevant research topics. This paper attempts to give an overview of recent developments and research trends. Although scientific work on this area has contributed to the understanding of the process, there are still unresolved problems regarding the limitations of the techniques, optimum machining conditions, etc. The outcome of experimental investigations on LAM shows potential applications for this process but there are several issues to be resolved.
Western versus asian types of multiple sclerosis: Immunogenetically and clinically distinct disorders
The polymorphism of HLA‐DRBI, ‐DRB3, and ‐DRB5 genes as well as magnetic resonance images of the brain and spinal cord were studied in 57 Japanese patients with multiple sclerosis (MS). Twenty‐three patients clinically displayed selective involvement of the optic nerve and spinal cord and were classified as having Asian‐type MS. Patients with Asian‐type MS had fewer brain lesions shown gy magnetic resonance imaging, but more gadolinium‐enhanced spinal cord lesions than did patients with Western‐type MS (47% vs 17%). Fruthermore, the DR2‐associated DRBI1501 allele and DRB50101 allele were associated with Western‐type MS (41.2%), but not with either Asian‐type MS (0%) or healthy control subjects (14.2%). Heterogeneity inthe immunogenetic background and in the magnetic resonance imaging features between the two subtypes of MS thus suggests the presence of two etiologically distinct diseases in Asians.