HTLV-I associated myelopathy with macular degeneration

The authors report a case of macular involvement in a patient with HTLV-I associated myelopathy (HAM). The patient was a 10-year-old girl who noticed sudden decreased vision in her right eye in November 1987. The corrected visual acuity was 0.01 in the right eye and 1.0 in the left eye. Fundus examination of the right eye disclosed mild optic disc pallor. The macula appeared to have pigmentary mottling with superficial irregular retinal reflex that was three disc diameters in size. Fluorescein angiography revealed a discoid hypofluorescent area in the macula, surrounded by mottled hyperfluorescent areas. She had no contributory family history of ocular disease, but had a history of blood transfusion during an operation for patent ductus arteriosus and ventricular septal defect at the age of 8 months. In November 1990, she developed gait disturbance due to spastic paraparesis and was admitted to our hospital. Antibodies to HTLV-I were markedly elevated in serum (titer, 1:8192) and in cerebrospinal fluid (titer, 1: 1024). She was diagnosed as HAM. Two months later, she developed encephalopathy and bilateral optic disc atrophy.     

Element by element a posteriori error estimation of the finite element analysis for three-dimensional elastic problems

An a posteriori error estimation method for finite element solutions for three-dimensional elastic problems is presented based on the theory developed by the authors for two-dimensional problems.¹ The error is estimated for the finite element solutions obtained using three-dimensional 8-node elements with a linear interpolation function in an arbitrary hexahedron. The method is successfully applied to three-dimensional elastic problems. In order to decrease computing time and memory use, the error is estimated element by element. The major difficulty in the element-wise error estimation technique is satisfying the self-equilibrium condition of applied forces, especially in three-dimensional problems. These forces are mainly due to traction discontinuity on the element boundaries. The difficulty is circumvented by employing an element-wise optimal procedure. It is also shown that a very accurate stress solution can be obtained by adding estimated error to the original finite element solutions.     

Effect of functional groups on the triboelectric charging property of polymer particles

Triboelectrification of small polymer particles (< 10 microns) in which various functional groups are introduced by addition of substituted comonomers is studied. The particles are produced by suspension polymerization and mechanical crushing of larger particles. The effect of the different production methods on the particle is described. The particles produced by the polymerization method have a spherical shape with a smooth surface, and those produced by the crushing method have an irregular shape. Studies show that particles that have easily ionizable functional groups are charged more effectively. It is believed the iontransfer route is the dominant mechanism in the triboelectrification charging of the particle. The magnitude of charge becomes saturated after 0.5% addition of substituted comonomers in the particles. The particles produced by the polymerization method have a tendency to be charged effectively compared with those produced by the crushing method. © 1994 John Wiley & Sons, Inc.     

Thermal-stress intensity factors for an insulated crack in a semi-infinite medium with a thin conductive stiffener

In the present paper is analyzed the thermal stress problem of the interaction between an insulated crack and a thin conductive elastic stiffener of finite length bonded to the surface of a semi-infinite medium under uniform heat flow on the basis of the two-dimensional theory of thermoelasticity. The singular point method is adopted to solve the problem and a system of singular integral equations is derived. Numerical results for the thermal-stress intensity factors are presented in terms of normalized parameters which consist of the dimensions and the geometrical arrangement of the crack and the stiffener, and the physical properties of the stiffener and the semi-infinite medium.     

Application of diamond films from CO-H2 plasma to tool blade coating

Diamond films were coated on WC-Co alloy tool blades using a microwave plasma of CO-H₂ mixed gas. Diamond film prepared at a CO concentration of 10% had good properties: Vickers hardness % 8500 kg mm^–2 and adhesion force 1.7 kg mm^–2. No peel-off of the diamond film was observed after a cutting test of an Al-Si alloy rod at a cutting speed of 450 m min^–1 for 0.5 h. It is thought that the high quality of the film originated from the selective etching of cobalt from the tool blade surface by CO-H₂ plasma.     

Fabrication of Bi2Sr2CaCu2Ox films on metal substrates by the chemical process using metal alkoxides

The formation behaviour of Bi₂Sr₂CaCu₂O_x from compounds prepared by hydrolysis of metal alkoxides was studied and Bi₂Sr₂CaCu₂O_x films on metal substrates were fabricated using a metal alkoxide solution. Bi₂Sr₂CaCu₂O_x was formed through intermediate phases such as Bi₂Sr₂Cu₁O_x, Bi₂CuO₄, SrCO₃, CaCO₃ and CuO. Bi₂CuO₄ was initially formed with SrCO₃, CaCO₃ and CuO, and then reacted with SrCO₃ to form Bi₂Sr₂Cu₁O_x. Bi₂Sr₂Cu₁O_x reacted with CaCO₃ and CuO to give Bi₂Sr₂CaCu₂O_x. Bi₂Sr₂CaCu₂O_x films were successfully fabricated on nickel substrates using the metal alkoxide solution at the nominal composition of BiSrCaCu=2223. Bi₂Sr₂CaCu₂O_x was precipitated on Ni substrates at firing temperature of 770 °C or above, and a sharp T _c was obtained at the firing temperature of 800 °C.