The Experts below are selected from a list of 537 Experts worldwide ranked by ideXlab platform
Hitoshi Ohsato - One of the best experts on this subject based on the ideXlab platform.
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synthesis and crystal structure microwave dielectric property relations in sn substituted ca3 zr1 xsnx si2o9 solid solutions with cuspidine structure
2007Co-Authors: Akinori Kan, Hirotaka Ogawa, Hitoshi OhsatoAbstract:The effects of Sn substitution for Zr on the microwave dielectric properties and crystal structure of Ca3(Zr1-xSnx)Si2O9 (CZSS) solid solutions were investigated in this study. The X-ray powder diffraction (XRPD) patterns of CZSS solid solutions were indicated to be a single phase, which corresponded to the cuspidine-type structure. The lattice parameters of CZSS solid solutions linearly decreased with increasing composition x, following Vegard's law. The dielectric constant (er) of CZSS solid solutions slightly decreased from 10.6 to 8.4, whereas the quality factor (Qf) of the solid solutions increased from 54791 to 93296 GHz, depending on the composition x. As a result, the Highest Qf value of 93296 GHz was obtained at x=1 where the dielectric constant and temperature coefficient of resonant frequency were 8.4 and -64.7 ppm/°C, respectively. The decreases in the dielectric constant and the increase in Qf values primarily depend on the composition x. This may be caused by the increase in the covalency of the (Zr,Sn)–O bond in the octahedron.
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effect of ni substitution on the microwave dielectric properties of cordierite
2007Co-Authors: M Terada, Keizou Kawamura, Isao Kagomiya, Kenichi Kakimoto, Hitoshi OhsatoAbstract:Abstract Cordierite (Mg2Al4Si5O18) is one of the silicates with low dielectric constant (ɛr), which are expected for good candidate of millimeter wave dielectrics. Microwave dielectric properties of Ni substituted cordierite solid solutions; (Mg1−xNix)2Al4Si5O18 have been investigated. (Mg1−xNix)2Al4Si5O18 with no secondary phase was obtained in the compositions x range from 0 to 0.1. It was found that a very small amount of Ni substitution was effectively increased of the quality factor (Qf) value and the Highest Qf value of 99,110 GHz was obtained in the composition x = 0.1. No remarkable composition dependence of the temperature coefficient of resonance frequency (τf) was observed in the range from x = 0.05 to 0.2, On the other hand, τf abruptly shifted toward negative value with increasing x from 0.3 to 0.5. The correlation between the crystal structure of cordierite and the microwave dielectric properties, particularly Qf is discussed.
Dainius Martuzevicius - One of the best experts on this subject based on the ideXlab platform.
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the comparative study of aerosol filtration by electrospun polyamide polyvinyl acetate polyacrylonitrile and cellulose acetate nanofiber media
2016Co-Authors: Jonas Matulevicius, Linas Kliucininkas, Tadas Prasauskas, Dalia Buivydiene, Dainius MartuzeviciusAbstract:Abstract Nanofiber media produced from different polymers via electrospinning were examined for the removal of aerosol particles from the air flow. The polymeric materials used as a filter media included polyamides 6 (PA6) and 6/6 (PA6/6), polyvinyl acetate (PVAc), polyacrylonitrile (PAN), and cellulose acetate (CA). The comparative filtration performance of the single-ply and multi-ply nanofiber media mats was evaluated. The measurements of filtration efficiency and estimation of quality factors (Qf) were performed for monodisperse 100 and 300 nm polystyrene latex and polydisperse NaCl particles. The results revealed that PVAc nanofiber media filter (PVAc_60) due the unique morphology of beaded nanofibers combined the Highest Qf and the high filtration efficiency: 0.055 Pa−1 (98.79%) for 100 nm particles and 0.042 Pa−1 (96.79%) for 300 nm particles accordingly. The PAN nanofiber media also showed relatively high filtration properties, while other nanofiber media (PA and CA) with high quality factors did not exceed filtration efficiency of 91%. The comparison of one-ply and multi-ply nanofiber media, characterized by lower basis weight, showed that multi-ply structures only slightly increase filtration properties for 100 and 300 nm particles, in some cases worsening filtration properties.
Jonas Matulevicius - One of the best experts on this subject based on the ideXlab platform.
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the comparative study of aerosol filtration by electrospun polyamide polyvinyl acetate polyacrylonitrile and cellulose acetate nanofiber media
2016Co-Authors: Jonas Matulevicius, Linas Kliucininkas, Tadas Prasauskas, Dalia Buivydiene, Dainius MartuzeviciusAbstract:Abstract Nanofiber media produced from different polymers via electrospinning were examined for the removal of aerosol particles from the air flow. The polymeric materials used as a filter media included polyamides 6 (PA6) and 6/6 (PA6/6), polyvinyl acetate (PVAc), polyacrylonitrile (PAN), and cellulose acetate (CA). The comparative filtration performance of the single-ply and multi-ply nanofiber media mats was evaluated. The measurements of filtration efficiency and estimation of quality factors (Qf) were performed for monodisperse 100 and 300 nm polystyrene latex and polydisperse NaCl particles. The results revealed that PVAc nanofiber media filter (PVAc_60) due the unique morphology of beaded nanofibers combined the Highest Qf and the high filtration efficiency: 0.055 Pa−1 (98.79%) for 100 nm particles and 0.042 Pa−1 (96.79%) for 300 nm particles accordingly. The PAN nanofiber media also showed relatively high filtration properties, while other nanofiber media (PA and CA) with high quality factors did not exceed filtration efficiency of 91%. The comparison of one-ply and multi-ply nanofiber media, characterized by lower basis weight, showed that multi-ply structures only slightly increase filtration properties for 100 and 300 nm particles, in some cases worsening filtration properties.
M Terada - One of the best experts on this subject based on the ideXlab platform.
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effect of ni substitution on the microwave dielectric properties of cordierite
2007Co-Authors: M Terada, Keizou Kawamura, Isao Kagomiya, Kenichi Kakimoto, Hitoshi OhsatoAbstract:Abstract Cordierite (Mg2Al4Si5O18) is one of the silicates with low dielectric constant (ɛr), which are expected for good candidate of millimeter wave dielectrics. Microwave dielectric properties of Ni substituted cordierite solid solutions; (Mg1−xNix)2Al4Si5O18 have been investigated. (Mg1−xNix)2Al4Si5O18 with no secondary phase was obtained in the compositions x range from 0 to 0.1. It was found that a very small amount of Ni substitution was effectively increased of the quality factor (Qf) value and the Highest Qf value of 99,110 GHz was obtained in the composition x = 0.1. No remarkable composition dependence of the temperature coefficient of resonance frequency (τf) was observed in the range from x = 0.05 to 0.2, On the other hand, τf abruptly shifted toward negative value with increasing x from 0.3 to 0.5. The correlation between the crystal structure of cordierite and the microwave dielectric properties, particularly Qf is discussed.
Linas Kliucininkas - One of the best experts on this subject based on the ideXlab platform.
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the comparative study of aerosol filtration by electrospun polyamide polyvinyl acetate polyacrylonitrile and cellulose acetate nanofiber media
2016Co-Authors: Jonas Matulevicius, Linas Kliucininkas, Tadas Prasauskas, Dalia Buivydiene, Dainius MartuzeviciusAbstract:Abstract Nanofiber media produced from different polymers via electrospinning were examined for the removal of aerosol particles from the air flow. The polymeric materials used as a filter media included polyamides 6 (PA6) and 6/6 (PA6/6), polyvinyl acetate (PVAc), polyacrylonitrile (PAN), and cellulose acetate (CA). The comparative filtration performance of the single-ply and multi-ply nanofiber media mats was evaluated. The measurements of filtration efficiency and estimation of quality factors (Qf) were performed for monodisperse 100 and 300 nm polystyrene latex and polydisperse NaCl particles. The results revealed that PVAc nanofiber media filter (PVAc_60) due the unique morphology of beaded nanofibers combined the Highest Qf and the high filtration efficiency: 0.055 Pa−1 (98.79%) for 100 nm particles and 0.042 Pa−1 (96.79%) for 300 nm particles accordingly. The PAN nanofiber media also showed relatively high filtration properties, while other nanofiber media (PA and CA) with high quality factors did not exceed filtration efficiency of 91%. The comparison of one-ply and multi-ply nanofiber media, characterized by lower basis weight, showed that multi-ply structures only slightly increase filtration properties for 100 and 300 nm particles, in some cases worsening filtration properties.