Rational approximations to Tricomi's psi function Interim report, 20 Mar. - 19 Jun. 1968

Closed form rational approximations to Tricomi psi functio

Got Caries? Breast milk and Early Childhood Caries?

Objective: To provide an analysis of the association between the longevity of breastfeeding and development of ECC. Determine the optimal time frame in which mothers should cease breastfeeding to reduce ECC development. Methods: Dr. Brickhouse, PubMed, Google Scholar and other scholarly databases were utilized to find current scientific evidence on the effects of breast milk on ECC. Relevant articles were summarized to write a review of literature. 16 articles published from 2015 to the present date were reviewed and cited. Results: From the studies, there is strong evidence to support breastfeeding beyond 12 months of age increases the prevalence of ECC. Furthermore, increased frequency and duration of breastfeeding leads to higher incidence of ECC. Conclusion: Findings indicate dental health care providers should recommend either ceasing breastfeeding at 12 months of age or provide ECC prevention education to caregivers. Further research is required to minimize data discrepancies between US and international countries.https://scholarscompass.vcu.edu/denh_student/1002/thumbnail.jp

Thermal stress analysis of space shuttle orbiter subjected to reentry aerodynamic heating

A structural performance and resizing (SPAR) finite-element computer program and NASA structural analysis (NASTRAN) finite-element computer programs were used in the thermal stress analysis of the space shuttle orbiter subjected to reentry aerodynamic heating. A SPAR structural model was set up for the entire left wing of the orbiter, and NASTRAN structural models were set up for: (1) a wing segment located at midspan of the orbiter left wing, and (2) a fuselage segment located at midfuselage. The thermal stress distributions in the orbiter structure were obtained and the critical high thermal stress regions were identified. It was found that the thermal stresses induced in the orbiter structure during reentry were relatively low. The thermal stress predictions from the whole wing model were considered to be more accurate than those from the wing segment model because the former accounts for temperature and stress effects throughout the entire wing

Earnings and Employment Dynamics for Africans in Post-apartheid South Africa: A Panel Study of KwaZulu-Natal

[Excerpt] The labour market is central in determining individual and household well-being in South Africa. Therefore, an understanding of earnings and employment dynamics is a key policy issue. However, the absence of panel data has constrained empirical work addressing these issues. This paper makes use of a regional panel data set for KwaZulu-Natal to begin the study of earnings and employment dynamics. The authors find that, on average, working-aged Africans in KwaZulu-Natal experienced large gains in earnings during the period 1993–8. These gains were progressive in nature, with the highest quintile of 1993 earners and those originally employed in the formal sector actually experiencing zero or negative growth in their average earnings. The average gain in earnings varied substantially depending on the employment transitions experienced by labour force participants. Obtaining formal sector employment is found to be an important pathway to growth in earnings, yet not exclusively so. The majority of those who get ahead do so by retaining employment in a given sector or moving into the informal sector. The dynamism of the informal sector over this period is shown to be an important contributor to the progressive growth in earnings. Government policies that seek to increase employment and earnings in the informal as well as formal sectors are recommended. Understanding the constraints preventing the vast number of unemployed from engaging in informal employment is shown to be a key issue for future work

Radon gas, useful for medical purposes, safely fixed in quartz

Radon gas is enclosed in quartz or glass ampules by subjecting the gas sealed at a low pressure in the ampules to an ionization process. This process is useful for preparing fixed radon sources for radiological treatment of malignancies, without the danger of releasing radioactive gases

Buckling behavior of Rene 41 tubular panels for a hypersonic aircraft wing

The buckling characteristics of Rene 41 tubular panels for a hypersonic aircraft wing were investigated. The panels were repeatedly tested for buckling characteristics using a hypersonic wing test structure and a universal tension/compression testing machine. The nondestructive buckling tests were carried out under different combined load conditions and in different temperature environments. The force/stiffness technique was used to determine the buckling loads of the panel. In spite of some data scattering, resulting from large extrapolations of the data fitting curve (because of the termination of applied loads at relatively low percentages of the buckling loads), the overall test data correlate fairly well with theoretically predicted buckling interaction curves. Also, the structural efficiency of the tubular panels was found to be slightly higher than that of beaded panels