130,601 research outputs found
Swirl Injection Modeling for Paraffin-Based Hybrid Rocket Engines Combustion Instabilities
No full textHybrid Rocket Engines have gained more and more attention in recent years due to their appealing safety and cost-effectiveness features, but they present some disadvantages, most notably a low regression rate. Swirl injection offers a promising solution, enhancing regression rate and stabilizing combustion by means of increased wall heat flux. This paper introduces a novel swirl model for regression rate evaluation consisting in two integrated sub-models: the first one involves a corrective factor linked to the geometric swirl number of the injector, while the other accounts for the naturally occurring swirl decay. The validity of the model was assessed across a range of different test cases, varying geometric parameters, engine scales, injection, and feeding conditions, and the results shows that the accuracy of local and mean regression rate prediction is improved. Corrections for the wall friction coefficient and the entrainment factor were introduced in an in-house code for paraffin-based fuels. A parametric analysis, carried out considering different swirl levels, revealed combustion chamber thermodynamics consistent with the expected trends observed in firing tests. Finally, an effective reduction in the delay time characteristic of the boundary layer was observed; moreover, the Rayleigh index results showed a marked decrease, indicating a decoupling of pressure fluctuations and heat release which tends to stabilize combustion as the swirl increases
Increasing Hand Hygiene Compliance Through Priming Interventions
No full textHealthcare-associated pathogens are present in medical settings, and healthcare workers’ hands are the most common route of transmission for spreading bacteria to patients resulting in infection. Hand hygiene is essential for preventing hospital-acquired infections (HAIs); however, compliance remains suboptimal, even after decades of studies aim to improve, so further innovation is needed. Psychological priming is exposure to certain cues (primes) which stimulates mental activity. Priming modifies behavior without the subjects’ knowledge of the impact the cues have on their performance. Priming has been shown to be useful in increasing hand hygiene compliance across medical settings. This literature review and study conducted at a University of Pittsburgh Medical Center (UPMC) aim to investigate the influence that the induction of priming conditioning has on hand hygiene compliance in medical settings
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Scholarly Communication and Publishing Lunch and Learn Talk #11: The ULS Open Access Author Fee Fund
No full textAt the May 2014 talk, you will learn about the ULS Open Access Author Fee Fund--what it is, why we do it, how it works, and how the program is going so far
The R&D Tax Incentives
No full textThis article sets out some background information and reflections of the author on the R&D tax incentive schemes included in the Common Corporate Tax Base (CCTB) Proposal. In particular the author analyzes the stimulus to private R&D through ad hoc tax incentives included in the CCTB Proposal and dives into the actual provisions included in the Proposal highlighting the most relevant issues connected with their design and interpretation. Moreover, the author explores the interaction between the CCTB Proposal and the granting by Member States of domestic R&D tax incentives
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