ABSTRACT
Glass-ceramic nanocomposites (GCNs) of (10 - x) BaTiO3 (BT)-xPbTiO3 (PT)-60V2O5-30B2O3 with x = 0, 2.5, 5, 7.5 and 10 mol% were formed during heat treatment of conventional melt quenching glasses. X-ray diffraction was used to ensure glass and GCNs formation. Glasses and GCNs densities were measured by Archimedes principle. Fine polar clusters of lead titanate and/or barium titanate incorporation into vanadium borate glass matrix strongly depend on the composition. It was found out that the electrical conductivity of the initial glasses can be considerably improved by proper early stage of nanocrystallization at temperatures approaching the crystallization temperatures determined by DSC method. GCNs show massive increase in electrical conductivity (up to 6 orders of magnitude) as a function of BaTiO3 content. By increasing BaTiO3 content, the activation energy values have been found to increase. The enhancement in electrical conductivity of GCNs can be attributed to the increase in the crystalline phases in the glassy matrix which increases the concentrations of the V ion pairs.
ABSTRACT
The development of dielectric constant materials for energy storage applications is in high demand. Lead zirconate and lead zirconate titanate doping with erbium thin films and bulk-based devices with variant dielectric constant were created in this work. Pb(0.9)-Er0.01Zr(0.09) (PEZ) and Pb0.9-Er0.01-Zr0.045-Ti0.045 (PEZT) thin films were produced on a glass substrate using a sol-gel doctor blade technique at low temperature. X-ray diffraction (XRD), transmission electron microscopy (TEM), and electron diffraction (ED) were used to examine the structure of the produced nanocrystals. PEZ and PEZT films had nanocrystals that were 9.5 nm and 15 nm in size, respectively, whereas PEZ and PEZT bulk nano-rods had 455 ± 5 nm in length and 45 ± 1 nm in diameter. The TEM and XRD results were found to be completely consistent in terms of particle size. Ferroelectric properties and dielectric characteristics were found to be frequency dependent. Dielectric experiments revealed that the dielectric constant was decreasing for bulk samples compared to film samples. The energy-storage efficiency of PEZ films was roughly 66.01%, and 67.8% for PEZT. The residual polarization of the Er-doped PEZ and PEZT films was the highest, reaching 36.25 µC/cm2 and 69.79 µC/cm2, respectively, and the coercive fields were 43 kV/cm and 45.43 kV/cm, respectively. On the other hand, PEZ and PEZT bulk samples had residual polarizations of 27.15 µC/cm2 and 37.29 µC/cm2, respectively, while having coercive fields of 32.3 kV/cm and 39.3 kV/cm, respectively. It was found that (PEZ) and (PEZT) samples may have potential use in energy storage applications.
ABSTRACT
OBJECTIVE: The aim of this study was to assess the prevalence and associated factors of female sexual dysfunction (FSD) in Lower Egypt. DESIGN: A cross-sectional clinic-/hospital-based survey. SETTING: Five district medical centres in Dakahlia Governorate: Shirbin, Bilquas, Samblawen, Dekrinis and Mansoura City. POPULATION: One thousand married women aged between 16 and 49 years. METHODS: Data were collected by personal interview in a questionnaire format in addition to physical examination (when allowed). MAIN OUTCOME MEASURES: FSD and associated risk factors. RESULTS: The response rate was 93.6%. 68.9% of women had one or more sexual problems; however, 23% of the women with sexual problems were not distressed by these issues. 31.5% of women suffered from dyspareunia. 49.6% of the women had decreased sexual desire, 36% had difficult arousal and 16.9% had anorgasmia (primary and secondary). Marital disharmony, 'hate' and unfavourable socio-economic circumstances were the most common aggravating factors (28.1%) for sexual dysfunction among the participants, followed by pregnancy-related events (15.7%). Most women (84.5%) received no help for their sexual problems. 90.3% of the women were circumcised. Only 7.1% (46 of 645) of women with sexual problems had received treatment, with no real improvement reported in 58.7% (27 of the 46 women). CONCLUSIONS: FSD is a highly prevalent problem within the scope of this study. Low reporting rates and very low treatment rates were identified in the sample from Lower Egypt.
