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Nobuharu Iwasawa - One of the best experts on this subject based on the ideXlab platform.

  • thickness dependence of the poling and current voltage characteristics of paint films made up of lead zirconate titanate Ceramic Powder and epoxy resin
    Journal of Applied Physics, 1995
    Co-Authors: Shun Egusa, Nobuharu Iwasawa
    Abstract:

    A specially prepared paint made up of lead zirconate titanate (PZT) Ceramic Powder and epoxy resin was coated on an aluminum plate and was cured at room temperature, thus forming the paint film of 25–300 μm thickness with a PZT volume fraction of 53%. The paint film was then poled at room temperature, and the poling behavior was determined by measuring the piezoelectric activity as a function of poling field. The poling behavior shows that the piezoelectric activity obtained at a given poling field increases with an increase in the film thickness from 25 to 300 μm. The current–voltage characteristic of the paint film, on the other hand, shows that the increase in the film thickness leads not only to an increase in the magnitude of the current density at a given electric field but also to an increase in the critical electric field at which the transition from the ohmic to space‐charge‐limited conduction takes place. This fact indicates that the amount of the space charge of electrons injected into the pain...

  • Thickness dependence of the poling and current-voltage characteristics of paint films made up of lead zirconate titanate Ceramic Powder and epoxy resin
    Journal of Applied Physics, 1995
    Co-Authors: Shun Egusa, Nobuharu Iwasawa
    Abstract:

    A specially prepared paint made up of lead zirconate titanate (PZT) Ceramic Powder and epoxy resin was coated on an aluminum plate and was cured at room temperature, thus forming the paint film of 25-300 pm thickness with a PZT volume fraction of 53%. The paint film was then poled at room temperature, and the poling behavior was determined by measuring the piezoelectric activity as a function of poling field. The poling behavior shows that the piezoelectric activity obtained at a given poling field increases with an increase in the film thickness from 25 to 300 ,um. The current-voltage characteristic of the paint film, on the other hand, shows that the increase in the film thickness leads not only to an increase in the magnitude of the current density at a given electric field but also to an increase in the critical electric field at which the transition from the ohmic to space-charge-limited conduction takes place. This fact indicates that the amount of the space charge of electrons injected into the paint film decreases as the film thickness increases. Furthermore, comparison of the current-voltage characteristic of the paint film with that of a pure epoxy film reveals that the space charge is accumulated largely at the interface between the PZT and epoxy phases in the paint film. On the basis of this finding, a model is developed for the poling behavior of the paint film by taking into account a possible effect of the space-charge accumulation and a broad distribution of the electric field in the PZT phase. This model is shown to give an excellent fit to the experimental data of the piezoelectric activity obtained here as a function of poling field and film thickness. 0

Shun Egusa - One of the best experts on this subject based on the ideXlab platform.

  • thickness dependence of the poling and current voltage characteristics of paint films made up of lead zirconate titanate Ceramic Powder and epoxy resin
    Journal of Applied Physics, 1995
    Co-Authors: Shun Egusa, Nobuharu Iwasawa
    Abstract:

    A specially prepared paint made up of lead zirconate titanate (PZT) Ceramic Powder and epoxy resin was coated on an aluminum plate and was cured at room temperature, thus forming the paint film of 25–300 μm thickness with a PZT volume fraction of 53%. The paint film was then poled at room temperature, and the poling behavior was determined by measuring the piezoelectric activity as a function of poling field. The poling behavior shows that the piezoelectric activity obtained at a given poling field increases with an increase in the film thickness from 25 to 300 μm. The current–voltage characteristic of the paint film, on the other hand, shows that the increase in the film thickness leads not only to an increase in the magnitude of the current density at a given electric field but also to an increase in the critical electric field at which the transition from the ohmic to space‐charge‐limited conduction takes place. This fact indicates that the amount of the space charge of electrons injected into the pain...

  • Thickness dependence of the poling and current-voltage characteristics of paint films made up of lead zirconate titanate Ceramic Powder and epoxy resin
    Journal of Applied Physics, 1995
    Co-Authors: Shun Egusa, Nobuharu Iwasawa
    Abstract:

    A specially prepared paint made up of lead zirconate titanate (PZT) Ceramic Powder and epoxy resin was coated on an aluminum plate and was cured at room temperature, thus forming the paint film of 25-300 pm thickness with a PZT volume fraction of 53%. The paint film was then poled at room temperature, and the poling behavior was determined by measuring the piezoelectric activity as a function of poling field. The poling behavior shows that the piezoelectric activity obtained at a given poling field increases with an increase in the film thickness from 25 to 300 ,um. The current-voltage characteristic of the paint film, on the other hand, shows that the increase in the film thickness leads not only to an increase in the magnitude of the current density at a given electric field but also to an increase in the critical electric field at which the transition from the ohmic to space-charge-limited conduction takes place. This fact indicates that the amount of the space charge of electrons injected into the paint film decreases as the film thickness increases. Furthermore, comparison of the current-voltage characteristic of the paint film with that of a pure epoxy film reveals that the space charge is accumulated largely at the interface between the PZT and epoxy phases in the paint film. On the basis of this finding, a model is developed for the poling behavior of the paint film by taking into account a possible effect of the space-charge accumulation and a broad distribution of the electric field in the PZT phase. This model is shown to give an excellent fit to the experimental data of the piezoelectric activity obtained here as a function of poling field and film thickness. 0

G V Jayanthi - One of the best experts on this subject based on the ideXlab platform.

  • Ceramic Powder synthesis by spray pyrolysis
    Journal of the American Ceramic Society, 1993
    Co-Authors: Gary L Messing, Shichang C Zhang, G V Jayanthi
    Abstract:

    A variety of spray pyrolysis (SP) techniques have been developed to directly produce Ceramic Powders from solutions. This paper reviews the current status of these processes in terms of the process parameters that enable the formation of particles with controlled morphology and composition. A model incorporating solute diffusion in the droplet and solvent evaporation from the droplet surface is presented to establish the critical parameters leading to solid particle formation. The model illustrates that solid particles can be obtained if solutes with high solubility and a large difference between the critical supersaturation and equilibrium concentration are used and if the process is designed to avoid solvent boiling. It is demonstrated that mixed metal oxide, non-oxide, and composite particles that are solid, hollow, porous, or fibrous can be produced by modifying the precursor characteristics, solution properties, and process parameters. The physical and chemical flexibility of SP processes offers numerous opportunities for the controlled synthesis of advanced Ceramic Powders and films. However, production rates are limited by the need to produce <5-[mu]m-diameter droplets and to avoid subsequent droplet coagulation. Developments in process controls, atomization, and system design are required for wider commercialization of SP-type processes.

  • Ceramic Powder Synthesis by Spray Pyrolysis
    Journal of the American Ceramic Society, 1993
    Co-Authors: Gary L Messing, Shichang C Zhang, G V Jayanthi
    Abstract:

    A variety of spray pyrolysis (SP) techniques have been developed to directly produce Ceramic Powders from solutions. This paper reviews the current status of these processes in terms of the process parameters that enable the formation of particles with controlled morphology and composition. A model incorporating solute diffusion in the droplet and solvent evaporation from the droplet surface is presented to establish the critical parameters leading to solid particle formation. The model illustrates that solid particles can be obtained if solutes with high solubility and a large difference between the critical supersaturation and equilibrium concentration are used and if the process is designed to avoid solvent boiling. It is demonstrated that mixed metal oxide, non-oxide, and composite particles that are solid, hollow, porous, or fibrous can be produced by modifying the precursor characteristics, solution properties, and process parameters. The physical and chemical flexibility of SP processes offers numerous opportunities for the controlled synthesis of advanced Ceramic Powders and films. However, production rates are limited by the need to produce

Osamu Takahashi - One of the best experts on this subject based on the ideXlab platform.

  • Compressive strength and resistance to chloride penetration of mortars using Ceramic waste as fine aggregate
    Construction and Building Materials, 2012
    Co-Authors: Hiroshi Higashiyama, Fumio Yagishita, Masanori Sano, Osamu Takahashi
    Abstract:

    This paper presents the results of experimental investigation on compressive strength and resistance to chloride ion penetration of mortars made of Ceramic waste as fine aggregate. The Ceramic waste of electrical insulators provided from an electric power company in Japan has been crushed and ground to produce fine aggregates for mortars in this study. In the process of crushing and grounding, Ceramic Powder is discharged as a by-product. The effects of mixing with the Ceramic Powder in mortars have been also investigated. Compression tests of mortars are conducted at 7, 28 and 91 days curing. Moreover, the resistance to chloride ion penetration of mortars has been determined by two methods: the spraying of a 0.1 N silver nitrate solution and the X-ray fluorescence spectrometry. The compressive strength of mortar made of the Ceramic waste aggregate increases and the resistance to chloride ion penetration is significantly higher in comparison with mortar made of the river sand. It is also confirmed that a partial replacement of cement by the Ceramic Powder up to 20% by weight is effective with respect to the compressive strength and the resistance to chloride ion penetration. © 2011 Elsevier Ltd. All rights reserved.

  • compressive strength and resistance to chloride penetration of mortars using Ceramic waste as fine aggregate
    Construction and Building Materials, 2012
    Co-Authors: Hiroshi Higashiyama, Fumio Yagishita, Masanori Sano, Osamu Takahashi
    Abstract:

    Abstract This paper presents the results of experimental investigation on compressive strength and resistance to chloride ion penetration of mortars made of Ceramic waste as fine aggregate. The Ceramic waste of electrical insulators provided from an electric power company in Japan has been crushed and ground to produce fine aggregates for mortars in this study. In the process of crushing and grounding, Ceramic Powder is discharged as a by-product. The effects of mixing with the Ceramic Powder in mortars have been also investigated. Compression tests of mortars are conducted at 7, 28 and 91 days curing. Moreover, the resistance to chloride ion penetration of mortars has been determined by two methods: the spraying of a 0.1 N silver nitrate solution and the X-ray fluorescence spectrometry. The compressive strength of mortar made of the Ceramic waste aggregate increases and the resistance to chloride ion penetration is significantly higher in comparison with mortar made of the river sand. It is also confirmed that a partial replacement of cement by the Ceramic Powder up to 20% by weight is effective with respect to the compressive strength and the resistance to chloride ion penetration.

Gary L Messing - One of the best experts on this subject based on the ideXlab platform.

  • Ceramic Powder synthesis by spray pyrolysis
    Journal of the American Ceramic Society, 1993
    Co-Authors: Gary L Messing, Shichang C Zhang, G V Jayanthi
    Abstract:

    A variety of spray pyrolysis (SP) techniques have been developed to directly produce Ceramic Powders from solutions. This paper reviews the current status of these processes in terms of the process parameters that enable the formation of particles with controlled morphology and composition. A model incorporating solute diffusion in the droplet and solvent evaporation from the droplet surface is presented to establish the critical parameters leading to solid particle formation. The model illustrates that solid particles can be obtained if solutes with high solubility and a large difference between the critical supersaturation and equilibrium concentration are used and if the process is designed to avoid solvent boiling. It is demonstrated that mixed metal oxide, non-oxide, and composite particles that are solid, hollow, porous, or fibrous can be produced by modifying the precursor characteristics, solution properties, and process parameters. The physical and chemical flexibility of SP processes offers numerous opportunities for the controlled synthesis of advanced Ceramic Powders and films. However, production rates are limited by the need to produce <5-[mu]m-diameter droplets and to avoid subsequent droplet coagulation. Developments in process controls, atomization, and system design are required for wider commercialization of SP-type processes.

  • Ceramic Powder Synthesis by Spray Pyrolysis
    Journal of the American Ceramic Society, 1993
    Co-Authors: Gary L Messing, Shichang C Zhang, G V Jayanthi
    Abstract:

    A variety of spray pyrolysis (SP) techniques have been developed to directly produce Ceramic Powders from solutions. This paper reviews the current status of these processes in terms of the process parameters that enable the formation of particles with controlled morphology and composition. A model incorporating solute diffusion in the droplet and solvent evaporation from the droplet surface is presented to establish the critical parameters leading to solid particle formation. The model illustrates that solid particles can be obtained if solutes with high solubility and a large difference between the critical supersaturation and equilibrium concentration are used and if the process is designed to avoid solvent boiling. It is demonstrated that mixed metal oxide, non-oxide, and composite particles that are solid, hollow, porous, or fibrous can be produced by modifying the precursor characteristics, solution properties, and process parameters. The physical and chemical flexibility of SP processes offers numerous opportunities for the controlled synthesis of advanced Ceramic Powders and films. However, production rates are limited by the need to produce