43 research outputs found

    Theoretical Investigation of Submerged Inlets at Low Speeds

    Get PDF
    The general characteristics of the flow field in a submerged air inlet are investigated by theoretical, wind-tunnel, and visual-flow studies. Equations are developed for calculating the laminar and turbulent boundary-layer growth along the ramp floor for parallel, divergent, and convergent ramp walls, and a general equation is derived relating the boundary-layer pressure losses to the boundary-layer thickness. It is demonstrated that the growth of the boundary layer on the floor of the divergent-ramp inlet is retarded and that a vortex pair is generated in such an inlet. Functional relationships are established between the pressure losses in the vortices and the geometry of the inlet. A general discussion of the boundary layer and vortex formations is included, in which variations of the various losses and of the incremental external drag with mass-flow ratio are considered. Effects of compressibility are also discussed

    Theoretical lift due to wing incidence of slender wing-body-tail combinations at zero angle of attack

    Get PDF
    The theoretical lift of a cylindrical afterbody at zero angle of attack due to incidence of the wing is calculated by means of slender-body theory. It is assumed that the vortex sheet becomes fully rolled up ahead of the tail, and the vortex paths in the presence of the body are determined analytically. The total lift of a variety of slender wing-body-tail combinations due to wing incidence is also calculated

    Why Some Cancer Patients Chose Fasting Instead of, or With, Conventional Treatments

    Get PDF
    Abstract Conventional cancer treatment consists of some combination of three therapies: chemotherapy, surgery and radiation. The purpose of this study was to understand why some individuals diagnosed with cancer elected to follow an alternative course of treatment, consisting of fasting on juices or water only rather than, or in addition to, conventional cancer treatment. The theory chosen to guide this study was the Markula Center for Applied Ethics framework for ethical decision making. Research questions were designed to understand the decision-making process of study participants in choosing fasting on juice or water only, rather than, or in addition to, the use of conventional interventions, and specifically to determine what role ethics and cost may have played. The research was a qualitative, phenomenological study, in which data were collected from nine semi-structured interviews. Data analysis consisted of coding the interview transcripts using a priori and open codes, categorizing the codes generated by the framework and data respectively, and then coalescing the resulting categories into themes, to answer the research questions. Themes which emerged from analysis of the data were Emotion-based process elements and Ethics and Logic. Understanding the decision-making process of individuals in this study could help medical professionals explain to patients diagnosed with cancer the treatment options available to them and how to choose ethically for optimum outcomes

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

    Get PDF
    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
    corecore