No abstract

A crack reduction by electron beam (EB) irradiation treatment for carbon fiber, used without the traditional method of accompanying heat, was developed to modify the mechanical properties at lower temperature. The EB treatment improved the resistance to fracture. Namely, the maximum ratio of fractured samples (maxRf) and the minimum bending strain on fracture (minεf) were defined as simple indicators of fracture resistance and became smaller by the EB treatment. Furthermore, a critical density of dangling bonds for a fracture was suggested and determined for carbon fiber treated by EB irradiation. The EB irradiation to reduce cracking and the determination of the critical density of dangling bonds are new concepts that can be broadly applied in the fields of aerospace and rapid-transit production engineering.

We developed a diamond surface that does not mist near the room temperature under a saturated humidity atmosphere, by sheet electron beam irradiation (SEBI) treatment. SEBI treatment decreased the time to clear vision of the diamond surface. Following SEBI treatment for 1.91 s (= 0.72 MGy) to a diamond surface, the time to clear vision was less than 2 s. The effective duration time was a few hours. Based on the results of the size distribution of the drops on the misting-free diamond surface following blowing for 3 s, we proposed an explanation for the short time to clear vision of the diamond surface treated by SEBI.

Carbon fiber reinforced plastics (CFRPs), with their advantages of light weight and high strength, are increasingly being applied as structural materials in the fields of aerospace engineering and rapid transport engineering. To strengthen CFRPs, electron beam (EB) irradiation is performed homogeneously. EB irradiation enhances the bending fracture stress and the bending fracture strain, and also slightly enhances the bending elasticity of CFRP. The analysis based on the Law of Mixture Strength for composites suggests that EB strengthening of CFRPs is chiefly attributable to ductility enhancement of the epoxy resin and carbon fiber.

o E p , electron spin resonance (ESR) signals related to dangling bonds were observed. When HLEBI cut the chemical bonds and generated dangling bonds with nonbonding electrons in PTFE and PDMS, the electrons induced the chemical bonding and intermolecular attractive force. HLEBI induced strong adhesive force of laminated sheets was explained by the discussion. Therefore, it was concluded that HLEBI was a useful tool for quick lamination of bio-adaptable PDMS and high strength PTFE.

No abstract

A misting free dental mirror is obtained near the human temperature under the saturated humidity atmosphere by use of the sheet electron beam irradiation treatment. It is shown that electron beam irradiation treatment decreases the time to clear vision in a misted mirror. This effect is due to an enhancement of the interfacial energy between the dental mirror glass and water.The steam generated in the mouth often prevents a medical operation. A blur in a medical dental mirror is a very serious problem. The phenomenon is strongly dependent on the wettability of the mirror surface. An argon irradiation modifies the wettability. 1,2 However, argon atoms are incorporated in the sample during irradiation. 3 Since the impurity atoms are slowly released, the surface conditions deteriorate. By using an electron beam (E.B.) irradiation, a reproducible surface condition can be obtained. Furthermore, the E.B. irradiation is applicable for a sterilization. In this paper, the effect of the E.B. irradiation on the clear time (t c ) is investigated for a misted dental mirror glass.The sheet electron beam irradiation was homogeneously performed by an electrocurtain processor (Type: CB 175/15/180L, ; Iwasaki Electric Group Company). 3 -5 Figure 1 shows the schematic drawing of the apparatus. The acceleration potential and the irradiating current were 170 kV and 4 mA, respectively. In order to avoid sample heating, the several irradiation steps, each lasting only at 0.38 s, were used to reach the final dose. The temperature was below 323 K just after the irradiation. The electron beam irradiation was performed under a protective nitrogen gas with the atmospheric pressure in the apparatus. The oxygen concentration was less than 400 ppm in the atmosphere. The irradiation dose D (Mrad) is proportional to the electron beam irradiation time t i (s) according to D 24 3 t i .(1)The effectiveness of the electron beam treatment was evaluated by measuring the time (t c ) necessary to get clear vision of the mirror surface misted by the steam. FIG. 1. Schematic diagram of electrocurtain processor.3368

No abstract