This paper describes the influence of electrolyzed reducing water of dilute NaCl (NaCl ER water) on the surface of optical glass. First, the etching characteristic of NaCl ER water on the surface of optical glass was made clear by the comparative immersion experiments with NaCl ER water and NaOH solution. The results show that as for the etching effects on optical glass, NaCl ER water is same as the NaOH solution and becomes weak. Next, the influence of NaCl ER water on the surface shape, chemical composition and chemical bonding of the surface of optical glass was made clear, by the observation using the AFM image and the result of ESCA (Electron Spectroscopy for Chemical Analysis). The results indicated that NaCl ER water did not have any bad influence on the surface shape, chemical composition and chemical bonding of optical glass. Lastly, by the washing experiment, the efficiency of NaCl ER water in abrasives particulate removal is verified.
This paper presents to develop a novel high-efficiency polishing technique which combines applied an AC electric field polishing and tribochemical polishing. Here, the AC electric field polishing has the effect of controlling the slurry flow behavior and the tribochemical polishing has the effect of promotion of chemical reaction among the abrasives, glass substrates and water generated by high-speed relative velocity between the platen and glass substrate. This research focuses the slurry behaviour shown by applied strength of the various AC electric field using digital image processing. As a result, it was found that the slurry behavior with the AC electric field was improved compared to one and no electric field. And the locus area of slurry flow on the polishing area was linearly increased with the increment applied AC electric frequency. Furthermore, this research verified the correlation among the applied AC electric frequency, removal rate, surface roughness. As a result, it was clarified that the removal rate was positively correlated with the slurry locus area. In particular, the removal rate of the combined polishing technique improves about two and a half times with excellent smooth surface than the conventional polishing.
The TiCN coating film containing free carbon deposited by UBMS (U-TiCN) is applied to the end mills and some kinds of such tools are used in high-speed milling of SUS304. This coating film is designed to improve lubricating ability rather than heat resistance. U-TiCN coating film including many free carbons has smooth surface and low coefficient of friction. Following the 1st report, film properties and cutting temperature of U-TiCN coating film are examined. U-TiCN oxidizes at 500°C lower than TiN and TiAlN. FE-TEM (Field Emission Scanning Electron Microscope) analysis reveals that the U-TiCN coating film forms the fine crystallization rather than generally TiCN coating film without free carbons. Lower cutting temperature is obtained with these U-type TiCN-coated tools than the ordinary AIP-coated tools in high-speed side milling without coolant.
A polymeric composite coating consisting of epoxy resin matrix and carbon onion as a filler has been prepared to develop self-lubrication. The tribological properties of the coating have been characterized in terms of contact load, ambient pressure and filler content. Different types of nano-carbons such as nano-diamond particles, fullerene mixture and carbon black were used as reference fillers. The improvement of the lubricity of epoxy resin coating has experimentally been proved with the incorporation of carbon onion ranging 0.3-1 wt%. The development of self-lubrication of the composite coating has been found without close relation to the contact load ranging 0.29-4.6 N between sliding parts under which little wear was caused. The incorporation of carbon onion has also contributed superior self-lubricative properties as well as wear-resistance in both air and vacuum without detrimentally degrading hardness.
In near-field levitation, an object can be levitated vertically upward above vibrating surface of an ultrasonic transducer. On the other hand, it has been reported that an object can be suspended vertically downward under the vibrating surface in the air. We call this phenomenon ultrasonic suspension. When an object is suspended, there is restoring force, which attracts the object to the center of the vibrating surface. Characteristics of the forces acting vertically and horizontally were investigated experimentally. A servo type measuring mechanism was composed and could measure vertical and horizontal actuation forces simultaneously. This paper reports the relationship among the actuation forces, suspension gap and center distance between vibrating surface and suspended object. As a result, it has been found that the actuation forces change with the vibrating amplitude, the diameter of vibrating surface, the diameter of circular plate and so on.
Printed-circuit boards are widely used for miniaturizing electronic equipments. According to the demand, diameter of holes in the boards is decreasing. There is a problem in their fabrication processes, in which they should be cleaned in water. After the cleaning process, water remains in the small holes. The remained water contains chemical material and/or dusts and might cause damage of the boards in the future. Conventionally, air pressure has been used to remove the water in the boards. But the method is not valid for holes that have bottoms inside neither for much smaller holes. Heating could be an alternative method, but this method might leave chemical material in the water and cause deflection of the board. In this research, a new dewatering method has been proposed. The method utilizes standing wave of ultrasonic wave in air. An experimental apparatus was organized to observe the ultrasonic dewatering and consisted of an ultrasonic transducer and a reflector. Proposed dewatering was observed successfully. The sound pressure in the standing wave was measured by a microphone. A condition for successful dewatering was discussed with reference to the distribution of the sound pressure.
The atmospheric transparency measurement for the Telescope Array (TA) experiment in Utah, USA is done by using LIDAR system and CLF system that use the pulse laser (355 nm). The LIDAR system observes the backscattering light of the laser, and the CLF system observes the side scattering light. The consistency of the time variation of an atmospheric transparency was confirmed into the observation method and the analysis in both systems.
This paper describes a method of computing motion in fluid and an experiment using it. Motion of an object is computed by a physical simulation environment. It is constructed of a physical engine, which processes computation of rigid body dynamics. Computation of fluid dynamics is additionally implemented to the environment so that motion in fluid is simulated faster than other computational methods. The environment read easily the three dimensional mesh data, which is commonly used by CAD systems, then computes and visualizes motion immediately. The experiment is optimizing shapes of Leonardo da Vinci's spiral wings. Parameters of the spiral wing are optimized by a particle swarm optimization (PSO) or a sequential search so that the wing flies higher under two conditions. PSO usually find better parameters than a sequential search and do about sixty times as faster as a sequential search. The environment computes virtual motion for twenty seconds in real time of one second. The shapes given by an optimization are difference each other according to the given conditions, and proper from viewpoint of fluid dynamics.