Radiation hardening of components and systems for nuclear rocket vehicle applications

The results of the analysis of the S-2 and S-4B components, although incomplete, indicate that many Saturn 5 components and subsystems, e.g., pumps, valves, etc., can be radiation hardened to meet NRV requirements by material substitution and minor design modifications. Results of these analyses include (1) recommended radiation tolerance limits for over 100 material applications; (2) design data which describes the components of each system; (3) presentation of radiation hardening examples of systems; and (4) designing radiation effects tests to supply data for selecting materials

Initial stage of plate lifting from a water surface

This study deals with the flow induced by a rigid flat plate of finite length, initially touching a horizontal water surface, when it starts to move upwards with constant acceleration. In the present model, negative hydrodynamic pressures on the lower (wetted) surface of the plate are allowed, and thus, the water follows the plate due to the resulting suction force. The acceleration of the plate and the plate length are such that gravity, surface tension and viscous effects can be neglected during the early stages of the motion. Under these assumptions, the initial two-dimensional, potential flow caused by the plate lifting is obtained by using the small-time expansion of the velocity potential. This small-time solution is not valid close to the plate edges, as it predicts there singular flow velocities and unbounded displacements of the water-free surface. It is shown that close to the plate edges the flow is nonlinear and self-similar to leading order. This nonlinear flow is computed by the boundary-element method combined with a time-marching scheme. The numerical time-dependent solution approaches the self-similar local solution with time

Evaluation of insulation materials and composites for use in a nuclear radiation environment, phase 1

This study has been carried out to evaluate flight-qualified Saturn 5 materials, components, and systems for use, with or without modification, in the radiation environment of the nuclear flight system. The results reported herein are primarily intended to aid designers in their evaluation and selection of off-the-shelf equipments which may meet the stringent requirements and specifications associated with application on a reusable nuclear powered space system, i.e., the reusable nuclear shuttle. One of the factors which must be evaluated in the design of the RNS is the effects of radiation on materials; and it is toward this aspect of the overall effort that this analysis has been directed

The Tati resettlement scheme of Botswana : a study in natural resource planning and implementation within a social, economic and political framework.

Dept. of Geography. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1977 .G74. Source: Masters Abstracts International, Volume: 40-07, page: . Thesis (M.A.)--University of Windsor (Canada), 1977

Investigation into Intelligent Image Preprocessor Techniques for Artificial Neural Networks

In this thesis we will discuss the process for data preparation of visual or image data ready for use in Artificial Neural Network systems. The thesis will present these concepts, their location in the broader field and the arguments as why certain practices are considered required for these systems; before presenting a number of novel algorithms that are intended as alternatives with desirable properties. These novel algorithms will then be testing in a practical domain (simulating the challenge of face-detection within a scene), followed up by discussions of their successes and failures. The findings presented show that some of the novel algorithms can show statistically significant improvement in accuracy compared to some of the traditional methods used in the field. This thesis concludes with recommendations in which situations the novel algorithms may (if at all) be suitable for use in future designs and potential avenues for further research

Wikipedia as informal self-education for clinical decision-making in medical practice

Background For almost any topic, a Wikipedia page will appear among the first ten items of a search online. Wikipedia is also a site whose quality and reliability has been called into question. Methods In this paper, we aim to discuss medical practitioners’ use of Wikipedia, what this consists of and what it might be. We consider the context and history of Wikipedia before discussing the relationship between Wikipedia and the medical profession. In so doing, we will consider Wikipedia as a means of informal self-education and the extent to which it might inform clinical decision-making. We compare with the existing literature results from our two small-scale empirical studies of Wikipedia and clinical decision-making. Results Notwithstanding issues over quality and reliability, Wikipedia’s rules on verifiability are such that its articles are very heavily referenced, and this is just as true of health-related articles. The Cochrane/Wikipedia Initiative in improving the quality and reliability of medical and health pages in Wikipedia is significant in increasing reliability. Our respondents largely concurred with the results from earlier studies on the use of Wikipedia by medical practitioners. Conclusion Perhaps the very doubt over Wikipedia’s accuracy is its greatest strength as a means of informal education of doctors. That medical and health articles on Wikipedia can be so fully referenced and still be doubted is arguably a good thing and one whose effects may be spread into other, more trusted, publications. Hence, one might envisage a future where no one source is taken automatically on trust. Keywords Wikipedia, informal education, continued professional development, medical education

Staphylococcus aureus Bacteremia in Children of Rural Areas of The Gambia, 2008–2015

Staphylococcus aureus bacteremia is a substantial cause of childhood disease and death, but few studies have described its epidemiology in developing countries. Using a population-based surveillance system for pneumonia, sepsis, and meningitis, we estimated S. aureus bacteremia incidence and the case-fatality ratio in children <5 years of age in 2 regions in the eastern part of The Gambia during 2008–2015. Among 33,060 children with suspected pneumonia, sepsis, or meningitis, we performed blood culture for 27,851; of 1,130 patients with bacteremia, 198 (17.5%) were positive for S. aureus. S. aureus bacteremia incidence was 78 (95% CI 67–91) cases/100,000 person-years in children <5 years of age and 2,080 (95% CI 1,621–2,627) cases/100,000 person-years in neonates. Incidence did not change after introduction of the pneumococcal conjugate vaccine. The case-fatality ratio was 14.1% (95% CI 9.6%–19.8%). Interventions are needed to reduce the S. aureus bacteremia burden in The Gambia, particularly among neonates

A meta-analysis of the relationship of academic performance and Social Network Site use among adolescents and young adults

This meta-analysis explores the relationship between SNS-use and academic performance. Examination of the literature containing quantitative measurements of both SNS-use and academic performance produced a sample of 28 effects sizes (N ¼ 101,441) for review. Results indicated a significant negative relationship between SNS-use and academic performance. Further moderation analysis points to test type as an important source of variability in the relationship. We found a negative correlation between SNS-use and GPA, while a positive one for SNS-use and language test. Moreover, we found that the relationship of SNS-use and GPA was more strongly negative in females and college students

Social media as a platform for health-related public debates and discussions: the Polio vaccine on Facebook

BACKGROUND: Social media can act as an important platform for debating, discussing, and disseminating information about vaccines. Our objectives were to map and describe the roles played by web-based mainstream media and social media as platforms for vaccination-related public debates and discussions during the Polio crisis in Israel in 2013: where and how did the public debate and discuss the issue, and how can these debates and discussions be characterized? METHOD: Polio-related coverage was collected from May 28 to October 31, 2013, from seven online Hebrew media platforms and the Facebook groups discussing the Polio vaccination were mapped and described. In addition, 2,289 items from the Facebook group “Parents talk about Polio vaccination” were analyzed for socio-demographic and thematic characteristics. RESULTS: The traditional media mainly echoed formal voices from the Ministry of Health. The comments on the Facebook vaccination opposition groups could be divided into four groups: comments with individualistic perceptions, comments that expressed concerns about the safety of the OPV, comments that expressed distrust in the Ministry of Health, and comments denying Polio as a disease. In the Facebook group “Parents talk about the Polio vaccination”, an active group with various participants, 321 commentators submitted 2289 comments, with 64 % of the comments written by women. Most (92 %) people involved were parents. The comments were both personal (referring to specific situations) and general in nature (referring to symptoms or wide implications). A few (13 %) of the commentators were physicians (n = 44), who were responsible for 909 (40 %) of the items in the sample. Half the doctors and 6 % of the non-doctors wrote over 10 items each. This Facebook group formed a unique platform where unmediated debates and discussions between the public and medical experts took place. CONCLUSION: The comments on the social media, as well as the socio-demographic profiles of the commentators, suggest that social media is an active and versatile debate and discussion-facilitating platform in the context of vaccinations. This paper presents public voices, which should be seen as authentic (i.e. unmediated by the media or other political actors) and useful for policy making purposes. The policy implications include identifying social media as a main channel of communication during health crises, and acknowledging the voices heard on social media as authentic and useful for policy making. Human and financial resources need to be devolved specifically to social media. Health officials and experts need to be accessible on social media, and be equipped to readily provide the information, support and advice the public is looking for