Dear Editor,Penetrating keratoplasty(PKP)in pediatric corneal blindness(<18 years of age)is the standard surgical procedure for visual rehabilitation in full thickness corneal scarring and to avoid deprivation ambl...Dear Editor,Penetrating keratoplasty(PKP)in pediatric corneal blindness(<18 years of age)is the standard surgical procedure for visual rehabilitation in full thickness corneal scarring and to avoid deprivation amblyopia.1 Congenital corneal opacities account for higher number of pediatric PKP in the western world as compared to India where it's more of corneal leucoma post microbial keratitis.2 Congenital hereditary endothelial dystrophy,congenital glaucoma and macular corneal dystrophy(MCD)are the more common indications for pediatric PKP in the gulf,middle east countries because of higher rate of consanguineous marriages.3,4 Al-Ghamdi et al.展开更多
Polycrystalline SrBi_(4)Ti_(3.975)Zr_(0.025)O_(15)(SBTZ)was prepared using solid-state reaction technique.SBTZ was characterized by X-ray diffraction(XRD)and scanning electron microscopy(SEM).XRD analysis indicated th...Polycrystalline SrBi_(4)Ti_(3.975)Zr_(0.025)O_(15)(SBTZ)was prepared using solid-state reaction technique.SBTZ was characterized by X-ray diffraction(XRD)and scanning electron microscopy(SEM).XRD analysis indicated the formation of a single-phase orthorhombic structure.Particle size was found using SEM.The dielectric,ferroelectric,piezoelectric,modulus and impedance spectroscopy studies on SBTZ were investigated in the frequency range 1Hz-1MHz from room temperature(RT)to 600℃.Piezoelectric charge and electromechanical coupling coefficients were calculated from resonance and anti-resonance frequencies.Impedance and modulus plots were used as tools to analyze the sample behavior as a function of frequency.Cole-Cole plots showed a non-Debye relaxation.Conductivity measurements were performed on SBTZ.展开更多
文摘Dear Editor,Penetrating keratoplasty(PKP)in pediatric corneal blindness(<18 years of age)is the standard surgical procedure for visual rehabilitation in full thickness corneal scarring and to avoid deprivation amblyopia.1 Congenital corneal opacities account for higher number of pediatric PKP in the western world as compared to India where it's more of corneal leucoma post microbial keratitis.2 Congenital hereditary endothelial dystrophy,congenital glaucoma and macular corneal dystrophy(MCD)are the more common indications for pediatric PKP in the gulf,middle east countries because of higher rate of consanguineous marriages.3,4 Al-Ghamdi et al.
文摘Polycrystalline SrBi_(4)Ti_(3.975)Zr_(0.025)O_(15)(SBTZ)was prepared using solid-state reaction technique.SBTZ was characterized by X-ray diffraction(XRD)and scanning electron microscopy(SEM).XRD analysis indicated the formation of a single-phase orthorhombic structure.Particle size was found using SEM.The dielectric,ferroelectric,piezoelectric,modulus and impedance spectroscopy studies on SBTZ were investigated in the frequency range 1Hz-1MHz from room temperature(RT)to 600℃.Piezoelectric charge and electromechanical coupling coefficients were calculated from resonance and anti-resonance frequencies.Impedance and modulus plots were used as tools to analyze the sample behavior as a function of frequency.Cole-Cole plots showed a non-Debye relaxation.Conductivity measurements were performed on SBTZ.
