Effect of alkaline-earth oxides on the structure of lithium silicate glasses and their glass-ceramic derivatives by ultrasonic and X-Ray diffraction techniques

Lithium silicate glasses of the composition [65% SiO[2] + 30%Li[2]O + 5% RO [mol%]]; where RO is one of the divalent oxide: MgO, CaO, SrO or BaO, and their glass ceramic derivatives were examined using ultrasonic technique and x-ray diffraction for studying their structures. Also, the density of the samples was measured. Ultrasonic velocity measurements were carried out using 4 MHz longitudinal and shear wave probes at room temperature. The elastic moduli, Poisson's ratio, Debye temperature and softening temperature of the prepared samples were calculated. The results show that, the ultrasonic velocities [longitudinal and shear], the shear and Young's elastic moduli decrease as the divalent oxide is changed from MgO, CaO, SrO or BaO, respectively. Meanwhile, the density, the molar volume, Debye temperature, softening temperature and Poisson's ratio increase. The variations in the different physical parameters were correlated and discussed in relation to composition and compactness of the respective glass

Preparation and characterization of some phosphoborosilicate glasses containing some micronutrients as plant fertilizers

Four phosphoborosilicate glasses containing one or more of the micronutrients: namely Cu, Zn, Fe, were prepared using analytical grade chemicals by melting in an electric furnace at about 1400°C for 2hr. The melts being calcined at about 450°C, were carefully crushed to grains of 2mm size. The release rate of the glass grains of 2mm size in 0.4%HC1 solution, 2% citric acid solution, and distilled water at room temperature was determined using a standard grain method for immersion time intervals varying between 1 to 4 weeks. The concentrations of K and P ions released into the leaching solutions were determined. The results obtained revealed that some of the prepared plant fertilizer samples led to a significant increase in the plant growth better than that observed in case of the traditional fertilizers. Furthermore, the extents of K and P ions released increased by increasing the time of immersion

Fracture of the penile shaft: results of early surgical repair

In this article, we review a total of 12 patients with penile fracture who presented over a period of 36 months. Associated urethral injuries were found in 3 out of the 12 patients [25%]. All patients were treated by early surgical repair within 48 hours from the time of injury. They were discharged in good condition and were followed up, both clinically and pharmacocavernosographically in the outpatient department with excellent results. We advocate early surgical exploration and repair of these injuries because of the excellent results, shorter hospitalization, less morbidity and earlier return to full sexual activity

Histological study of intra-abdominal maldescended testis

This study was carried out on 16 male patients with unilateral intra- abdominal testis. Eleven cases [68.5%] had complete loss of germ cell population with extensive tubular, peri-tubular and interstitial fibrosis with stromal vessels sclerosis. Their age incidence was ranged from 20 to 35 years. The other five cases [31.5%] showed severe germ cell impairment, variation in the size of seminiferous tubules with basement membrane thickening and peri-tubular fibrosis. Some tubules showed complete fibrosis and hyalinization. Few sperms were seen in few non fibrotic seminiferous tubules. Their age incidence was ranged from 14 to 20 years. It was concluded that the longer a testis remained cryptorchids, the more pronounced was histological abnormality