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An electrostatic sheet stapler (ESS) that can paste a sheet material on a target by electrostatic force has been developed as an adherence and removal method for future sheet devices. The stapler was composed of two couples of needle to grid electrodes as positive and negative corona chargers with an insulator support dividing the two corona chargers. The proposed sheet material has two adherence areas where the surface can be charged up and a functional area where a thin and flexible functional device is placed; typically devices from printable electronics technology. The sheet device is adhered onto the target electrostatically; therefore, the force can be easily controlled, which provides a possible mechanization process for the adherence and removal of sheet devices without an adhesive material. Here we describe the theoretical concept of the ESS and measure the withstanding weight using a test model ESS. The time variation and distribution of the surface potential on the charged sheet and the adherence force are also reported.

An electrostatic field-driven (EFD) ionizer specifically designed for a moving charged target is proposed. The ionizer, which is proximally positioned to the charged target, is composed of a grounded mesh electrode and an array of positive and negative needle electrodes. The positive and negative needles face each other to make a high space charge density of positive and negative ions just above the grounded mesh. The electric field formed between the grounded mesh and the charged target transports ions by electrostatic force. The ion transportation brings a faster charge elimination rate than the air drag force widely used in commercial ionizers. An evaluation method of the charge elimination for a moving target is also proposed. The method employs parameters of capacitance of the target, equivalent resistance of the ionized air, effective length of the ionizing zone and moving speed of the target. The performance of the EFD ionizer and a commercial fan-type ionizer were compared using the evaluation method. The EFD ionizer was found to have significantly higher performance than the commercial fan-type ionizer.

We studied the radiation hardness of the ZnO/ZnMgO heterostructure field-effect transistors (HFETs) by irradiating 200 MeV proton beam for fluences up to 3.6 × 1014 p/cm2. The change of the characteristics was monitored and compared with those of GaAs HEMTs. The saturation drain current for the ZnO/ZnMgO HFETs decreased by 10% while that of GaAs HEMTs decreased by 50% at proton beam fluence of 3.6 × 1014 p/cm2. The results demonstrate the superior radiation hardness of the ZnO/ZnMgO HFETs. The fact that little resistance change was observed for the as-grown ZnO/ZnMgO heterostructure implies the reduced drain current observed for HFETs might be caused by degradation of gate dielectric.

A circular consecutive k-out-of-r from-n:F system consists of n components ordered oil a circle. The svstem falls if and onlN, if there are r consecutive corriponerits at least k of which are falled. The time complexity of a recentIy publislied algorithm for circular consecutive k-out-of r-from-n-:F system is O(nr). This paper proposes a method to Improve upon this O(nr) algorithm.

Investigation on removal method of SF/sub 6/ was carried out by using nonthermal plasma generated by pulsed power. We investigated the dependence of the discharge power and the polarity of applied pulsed voltage to the reactor on the removal rate of SF/sub 6/. The discharge power is varied with discharge repetition rate or charging voltage of the capacitor. As the discharge power increases, the removal rate of SF/sub 6/ is increases. The high repetition rate of pulse is more effective for removal of SF/sub 6/ than the big value of charging voltage. When the same discharge energy is supplied to the sample gas by changing the residence time or repetition rate, the removal rate is high in short residence time and high repetition rate. The removal rate of SF/sub 6/ for negative pulses is higher than that for positive ones. Consequently, the nonthermal plasma generated by pulsed power is effective to remove dilute SF/sub 6/ gas completely.

A linear consecutive 2-out-of-(m, n): F system is considered. A recursive algorithm for calculating the reliability of the system is presented. The algorithm depends on the one-to-one correspondence relation of the systems and the class of 0-1 matrices having no two consecutive 1s at any row or any column.

A method to create a 3D shape based on natural language is proposed. Generally, it is difficult for an non-professional user to create computer graphics (CG) by using traditional CG modelers, so we have developed "Do", a 3D shape modeler utilizing the English language, by which such users would be able to create a CG image. If it were possible to create 3D CG using English by a verbal interface, non-expert users, who do not have any special knowledge of CG, and handicapped users, who are unable to use hardware devices such as a mouse or keyboard, would be able to create CG. However, this system is oriented to shape modeling, and so some scene-constructing functions are attached.

To investigate an electrical discharge occurring from or in a space-charge cloud, a large-scale charged particle cloud was formed by using a cloud generator consisting of a blower and corona charger. The distribution of the electric field strength around a charged particle cloud has been investigated to determine the behavior of charged particles. The soil-conditioning particles were charged by corona charging and blown by high-speed air flow in a test room, 5 m wide, 10 m long, and 3 m high. The average charge-to-mass ratio of the particles blown by this method was 170 /spl mu/C/kg. The space-charge density of the cloud was calculated at the order of 10 /spl mu/C/m/sup 3/ from the electric field strength outside of the cloud. While the electric field strength at the outside of the cloud increased up to 52 kV/m within 2 m downstream from the cloud generator, it decreased below 25 kV/m farther than 2 m away from the cloud generator due to dispersion of charged particles. The change in the electric field strength due to dispersion of charged particles can be qualitatively explained by a simple cloud model. The velocity of charged particles transported by air flow and mobility of charged particles are found to be effective factors increasing the electric field strength around the large-scale charged particle cloud.

Covered conductors and insulators installed in a 6.6 kV distribution line passing through a coastal area along the sea of Japan are heavily polluted with sea salt conveyed by a northwesterly seasonal wind in winter. To understand the practical situation of the deposition of sea salt in winter, salt deposit onto the covered conductor and pin insulators was measured along with the salt quantity in the air and the weather conditions. Small sea water particles began to fly above a wind velocity of 5 m/s. Continuous observation of the partial discharge occurring around a distribution transformer revealed that the partial discharge was prone to occur when the hourly mean wind velocity exceeded 8 m/s. Sea salt rapidly deposits onto the insulators or covered conductor during occurrence of sea water spray from a high wave above 3 m. The equivalent salt deposit density (ESDD) happened to reach 1 mg/cm/sup 2/ within several hours in this area.

A consecutive k-out-of-r-from-n:F system consists of n linearly or circularly ordered components such that the system fails if and only if there are r consecutive components at least k of which are failed. This paper studies a lower bound for the reliability of a consecutive k-out-of-r-from-n:F system in the more general case when the component probabilities can be different from each other. New recursive equations are proposed, which have time complexity of O(nr/sup k/) for the linear system, and O(nr/sup 2k/) for the circular system.

Since the principle of a cell sorter was originally developed as an ink jet recorder, we have developed the similar particle sorting device for the separation of spherical particles. In order to confine particles at the center of now, the coaxial flow arrangement was used. In our equipment, charged droplets are electrostatically deflected to six different positions. Thus, at maximum, six different sizes of particles can be separated into six different groups. The particle sizes actually investigated were 5, 10, 15, 20 and 25 /spl mu/m. Experimental results reported before revealed that the separation of particles are quite successful, but not perfect. In order to clarity the causes of mis-separation, the mutual correlation of jet and a particle was investigated. It became clear that the particle inside the jet influences on the breakup position of natural jet, when the external vibration of the nozzle was off. The distance of breakup of natural jet became much shorter due to the existence of a particle inside the jet. Even if the external vibration was on, the existence of a particle inside jet also affected the breakup position.

The behavior of water droplets placed on the surface of a hydrophobic polymer plate under a DC field was investigated experimentally. In order to confirm the effect of hydrophobicity on the movement of the water droplet, three kinds of hydrophobic insulating materials-PTFE, silicone rubber (SR) and ethylene propylene rubber (EPDM)-were used. Water droplets were placed on the insulating plate in contact with the aluminum foil electrode or placed between the thin foil electrodes. A single droplet placed in contact with the electrode on the SR or EPDM plate was elongated and a water filament extended along the surface by the electrostatic force, while that on the PTFE plate left the electrode. The water droplet placed on the border of electrode at the PTFE plate was deformed and formed a semi-cone at a triple junction. The apparent contact angle varied with time for a constant applied voltage and some amounts of charge were emitted by micro discharge or by ejection of small droplets. The behavior of the droplets under DC field strongly depends on not only the hydrophobicity but also the surface property of an insulating plate.

Since the elongated particles have experimentally shown better ER effect than spherical ones, chain formation mechanism of suspensions was investigated by using a large scale model. In series of the experiment with this large scale model, interesting and peculiar particle motions were observed. Experimental set up consists of parallel electrodes immersed in Silicone fluid whose conductivity was changed by adding butylalcohol. The motion of propylene rod with a diameter of 0.7 mm and 6 mm long was examined by using video camera and also high-speed camera. At very low conductivity, there is no motion of the rod. When the conductivity is increased, there is many different kind of motion observed. Rotational motion was most frequently observed at a certain range of conductivity. Further increase of applied field, there is a circular motion of the rod. The rotational speed increases with the applied field. However, when the circular motion starts, the rotational speed decreases. The highest rotational speed observed was 11 rps.

Summary form only given. Sulphur hexafluoride (SF/sub 6/) is useful as an insulator of a circuit breaker and as an etcher of semiconductors. Since SF/sub 6/ is one of greenhouse gases, emission of SF/sub 6/ must be limited and reduced. Investigation on removal method of SF/sub 6/ was carried out by using a pulsed corona reactor. An experimental setup is presented. The electrode of the corona reactor is arranged in a co-axial wire-cylinder configuration. The cylindrical tube is used as a cathode electrode and the wire anode electrode is aligned with the center axis of the cylindrical cathode. The concentration of SF/sub 6/ is measured with an absorption spectrometry. The corona reactor and a cell for measurement of SF/sub 6/ absorption in a sample gas are set in a closed gas loop equipped with two buffer chambers. The sample gas flows constantly in closed gas loop. The buffer chambers play a role to fix the concentration of SF/sub 6/ at an inlet of the corona. reactor during one measurement. The sample gas consists of SF/sub 6/ and helium. The pressure of sample gas is 1 atm. The pulsed voltage circuit is a type of capacitor charge transfer.