Solution of the Dirac equation in the rotating Bertotti-Robinson spacetime

The Dirac equation is solved in the rotating Bertotti-Robinson spacetime. The set of equations representing the Dirac equation in the Newman-Penrose formalism is decoupled into an axial and angular part. The axial equation, which is independent of mass, is solved exactly in terms of hypergeometric functions. The angular equation is considered both for massless (neutrino) and massive spin-(1/2) particles. For the neutrinos, it is shown that the angular equation admits an exact solution in terms of the confluent Heun equation. In the existence of mass, the angular equation does not allow an analytical solution, however, it is expressible as a set of first order differential equations apt for numerical study.Comment: 17 pages, no figure. Appeared in JMP (May, 2008

The Influence of Industrial Automation on Educational Enrollment: A State-Level and Country-Level Analysis

The thesis investigates the effects of industrial automation on post-secondary education enrollment. To assess the effects, we build linear regression models to estimate the impact of the surge in the stock of industrial robots on post-secondary enrollment across 50 U.S. states and 41 countries. Drawing upon these estimates and the literature documenting the structural shift in the labor market, we find that recent developments in the fields of automation and robotics have contributed to a shift in demand for post-secondary education, with panel data models that control for both country and time fixed unobservables indicating a significant decline in enrollment for 4-year degree programs internationally

Risk Factors for Maternal Vitamin D Deficiency within the United Arab Emirates

Introduction: Vitamin D deficiency during pregnancy is a public health problem and it has been associated with negative pregnancy outcomes for both mothers and infants. Aim: To estimate the prevalence of vitamin D deficiency in pregnant women in the United Arab Emirates (UAE) and to identify the contribution of risk factors to the 25(OH)D levels. Methods: It is a cross-sectional study in which vitamin D levels of 1088 adult pregnant women were assessed. Information on vitamin D intake was available in a sub-sample of 266 women. Results: The mean serum 25(OH)D was 26.2 nmol/L (95% CI 25.2-27.1 range 5-129.1 nmol/L) with 69% of women being vitamin D deficient (<30 nmol/L). In the bivariate analysis, showed that no predictors could have been indicated as no values exceeded significance (p<0.2). Stepwise multiple linear regression analysis could not be applied to identify predictors of vitamin D levels as no values exceeded p=0.2. Conclusion: Due to the high prevalence of vitamin deficiency in UAE, there is an urge for interventions focusing on supplementation, fortification and diet diversity for preventing health consequences during a critical period of development

Subsequent Fertility of Goats with Prenatal Mortality Diagnosed by Ultrasound and Treated by PGF 2 α

Thirteen Saanen and Saanen crossbred female goats, between the ages of 6 months and 7, years were presented to the clinic, College of Veterinary Medicine, Sudan University of Science and Technology, for sonographic pregnancy diagnosis. Transabdominal ultrasound was performed using 3.5 MHz probe which revealed non-viable fetuses as judged by absence of heart beats and movements. Twelve goats were given single i/m injection of PGF2α analogue and 5% oxytetracycline. Ten goats responded to the treatment and six of them became pregnant and gave birth within the normal gestational period. One goat was diagnosed as non-pregnant, one goat developed hydrometra, and the subsequent fertility of two goats was unknown. Two full-term goats did not respond to treatment. Another dose of PGF2α was administered to them and again they did not respond. Manual attempts were done to deliver the full-term goat with dilated cervix and they were unsuccessful. Cesarean section and hysterectomy were then performed for the three full-term goats with unfavorable outcome. It can be concluded that ultrasound is a rapid, reliable, and nonhazardous procedure for the diagnosis of fetal mortality in goats and PGF2α treatment in conjunction with oxytetracycline is an efficient treatment

Photoacoustic Study of CdS QDs for Application in Quantum-Dot-Sensitized Solar Cells

The optical properties and photovoltaic characterization of CdS quantum dots sensitized solar cells (QDSSCs) were studied. CdS QDs were prepared by the chemical solution deposition (CD) technique. Photoacoustic spectroscopy (PA) was employed to study the optical properties of the prepared samples. The sizes of the CdS QDs were estimated from transmission electron microscope (TEM) micrographs gives radii ranged from 1.57 to 1.92 nm. The current density-voltage (J-V) characteristic curves of the assembled QDSSCs were measured. Fluorine doped Tin Oxide (FTO) substrates were coated with 20 nm-diameter TiO2 nanoparticles (NPs). Presynthesized colloidal CdS quantum dots of different particles size were deposited on the TiO2-coated substrates using direct adsorption (DA) method. The FTO counter electrodes were coated with platinum, while the electroelectrolyte containing I-/I-3 redox species was sandwiched between the two electrodes. The short current density (Jsc) and efficiency (η) increases as the particle size increases. The values of Jsc increases linearly with increasing the intensities of the sun light which indicates the greater sensitivity of the assembled cells