3,208 research outputs found
Draft toxicological profile for JP-5, JP-8, and jet A fuels
No full textA Toxicological Profile for JP-5 and JP-8 was released in 1998. This present edition supersedes any previously released draft or final profile.Chemical manager(s)/author(s): John Risher, Obaid Faroon, ATSDR, Division of Toxicology and Human Health Sciences, Atlanta, GA; Fernando Llados, Lisa Ingerman, Mario Citra, SRC, Inc., North Syracuse, NY
Surface magnetic phase transitions in Dy/Lu superlattices
No full textDy/Lu superlattices comprising ferromagnetic Dy blocks coupled antiferromagnetically across the Lu blocks may be modelled as a chain of XY spins with antiferromagnetic exchange and six-fold anisotropy. We have calculated the stable magnetic phases for the cases of large anisotropy and a field applied along an easy direction. For an infinite chain an intermediate phase <1, 5,...> is predicted, where the notation gives the angle between the moment and the applied field in units of pi/3. Furthermore, the effects of surface reconstruction an determined for finite chains. A [Dy(20)Lu(12)](20) superlattice has been studied using bulk magnetization and polarized neutron reflectivity. The (1, 5...) phase has been identified and the results provide direct evidence in support of the theoretical predictions. Dipolar forces are shown to account for the magnitude of the observed exchange coupling. (C) 1999 Elsevier Science B.V. All rights reserved
Shock tube study of JP-10 ignition delay time
No full textJP-10 (exo-tetrahydrodicyclopentadiene, C10H16) ignition delay times were measured in a preheated shock tube. The vapor pressures of the JP-10 were measured directly by using a high-precision vacuum gauge, to remedy the difficulty in determining the gaseous concentrations of heavy hydrocarbon fuel arising from the adsorption on the wall in shock tube experiments. The whole variation of pressure and emission of the OH or CH radicals were observed in the ignition process by a pressure transducer and a photomultiplier with a monochromator. The emission of the OH or CH radicals was used to identify the time to ignition. Experiments were performed over the pressure range of 151-556 kPa, temperature range of 1000-2100 K, fuel concentrations of 0.1%-0.55% mole fraction, and stoichiometric ratios of 0.25, 0.5, 1.0 and 2.0. The experimental results show that for the lower and higher temperature ranges, there are different dependency relationships of the ignition time on the temperature and the concentrations of JP-10 and oxygen
Dynamics of Network Formation Processes in the Co-Author Model
No full textThis article studies the dynamics in the formation processes of a mutual consent network in game theory setting: the Co-Author Model. In this article, a limited observation is applied and analytical results are derived. Then, 2 parameters are varied: the number of individuals in the network and the initial probability of the links in the network in its initial state. A simulation result shows a finding that is consistent with an analytical result for a state of equilibrium while it also shows different possible equilibria.Dynamics, Network, Game Theory, Model,Simulation, Equilibrium, Complexity
An equivalent formulation of the Fan-Raspaud Conjecture and related problems
No full textIn 1994, it was conjectured by Fan and Raspaud that every simple bridgeless cubic graph has three perfect matchings whose intersection is empty. In this paper we answer a question recently proposed by Mkrtchyan and Vardanyan, by giving an equivalent formulation of the Fan-Raspaud Conjecture. We also study a possibly weaker conjecture originally proposed by the first author, which states that in every simple bridgeless cubic graph there exist two perfect matchings such that the complement of their union is a bipartite graph. Here, we show that this conjecture can be equivalently stated using a variant of Petersen-colourings, we prove it for graphs having oddness at most four and we give a natural extension to bridgeless cubic multigraphs and to certain cubic graphs having bridges
Ephemisms as communication vehicle in the Tiv language and literature
No full textThe beauty of Tiv language and literature is achieved when communication or discourse is laced with euphemistic expressions. Euphemisms aid in turning impolite utterances into polite ones. This study, therefore, investigates the communicative potentials of euphemisms in the Tiv language and literature. The study discusses formations of euphemisms, classifies euphemisms and explores the effects of euphemisms. Connotative theory of meaning has been deployed in this study because the interpretation of euphemisms is contextually and connotatively loaded. Methodologically, the author used primary and secondary materials. The author used a participant-observation tool for data collection. Being a native speaker of the Tiv language, the author collected, translated and classified euphemisms. Secondary materials were sourced from textbooks, journal articles, online sources and dictionaries. The following findings were made: euphemisms constitute phrasal or idiomatic synonyms; they beautify or spice our daily communication; they can becloud meanings. This study will benefit preachers, writers, lecturers/teachers, researchers, semanticists, public speakers, politicians and students
Open Access to Peer-Reviewed Research through Author/Institution Self-Archiving: Maximizing Research Impact by Maximizing Online Access
No full textAll refereed journals will soon be available online; most of them already are. This means that anyone will be able to access them from any networked desk-top. The literature will all be interconnected by citation, author, and keyword/subject links, allowing for unheard-of power and ease of access and navigability. Successive drafts of pre-refereeing preprints will be linked to the official refereed draft, as well as to any subsequent corrections, revisions, updates, comments, responses, and underlying empirical databases, all enhancing the self-correctiveness, interactivity and productivity of scholarly and scientific research and communication in remarkable new ways. New scientometric indicators of digital impact are also emerging <http://opcit.eprints.org> to chart the online course of knowledge. But there is still one last frontier to cross before science reaches the optimal and the inevitable: Just as there is no longer any need for research or researchers to be constrained by the access-blocking restrictions of paper distribution, there is no longer any need to be constrained by the impact-blocking financial fire-walls of Subscription/Site-License/Pay-Per-View (S/L/P) tolls for this give-away literature. Its author/researchers have always donated their research reports for free (and its referee/researchers have refereed for free), with the sole goal of maximizing their impact on subsequent research (by accessing the eyes and minds of fellow-researchers, present and future) and hence on society. Generic (OAi-compliant) software is now available free so that institutions can immediately create Eprint Archives in which their authors can self-archive all their refereed papers for free for all forever <http://www.eprints.org/>. These interoperable Open Archives <http://www.openarchives.org> will then be harvested into global, jointly searchable "virtual archives" (e.g., <http://arc.cs.odu.edu/>). "Scholarly Skywriting" in this PostGutenberg Galaxy will be dramatically (and measurably) more interactive and productive, spawning its own new digital metrics of productivity and impact, allowing for an online "embryology of knowledge.
Why hasn't electronic bill presentment and payment taken off?
No full textThe delivery and payment of bills over the Internet could offer many advantages—low processing costs and enhanced marketing opportunities for billers, savings in time and postage for customers. Nevertheless, electronic billing has not found favor with potential users. A lack of coordination among billers and customers, combined with the high fixed costs of the new technology, may help account for the cool reception.Electronic funds transfers ; Electronic commerce ; Technology ; Payment systems
Author Correction: Discovery of fungal surface NADases predominantly present in pathogenic species.
No full textStromland O, Kallio JP, Pschibul A, et al. Author Correction: Discovery of fungal surface NADases predominantly present in pathogenic species. Nature communications. 2021;12(1): 2004
Systematic reviews with language restrictions and no author contact have lower overall credibility: a methodology study
No full textZhen Wang,1–3 Juan P Brito,4 Apostolos Tsapas,5 Marcio L Griebeler,4 Fares Alahdab,1,3 Mohammad Hassan Murad,1,3,61Robert D and Patricia E Kern Center for the Science of Health Care Delivery, 2Division of Health Care Policy and Research, Department of Health Sciences Research, 3Knowledge and Evaluation Research Unit, 4Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Mayo Clinic, Rochester, MN, USA; 5Aristotle University of Thessaloniki, Thessaloniki, Greece; 6Division of Preventive, Occupational and Aerospace Medicine, Mayo Clinic, Rochester, MN, USABackground: High-quality systematic reviews (SRs) require rigorous approaches to identify, appraise, select, and synthesize research evidence relevant to a specific question. In this study, we evaluated the association between two steps in the conduct of an SR – restricting the search to English, and author contact for missing data – and the overall credibility of a SR.Methods: All SRs cited by the Endocrine Society's Clinical Practice Guidelines published from October 2006 through January 2012 were included. The main outcome was the overall A Measurement Tool to Assess Systematic Reviews (AMSTAR) score, as a surrogate of SR credibility. Nonparametric Kruskal–Wallis tests and multivariable linear regression models were used to investigate the association between language restriction, author contact for missing data, and the overall AMSTAR score.Results: In all, 69 SRs were included in the analysis. Only 31 SRs (45%) reported searching non-English literature, with an average AMSTAR score of 7.90 (standard deviation [SD] =1.64). SRs that reported language restriction received significantly lower AMSTAR scores (mean =5.25, SD =2.32) (P<0.001). Only 30 SRs (43%) reported contacting authors for missing data, and these received, on average, 2.59 more AMSTAR points (SD =1.95) than those who did not (P<0.001). In multivariable analyses, AMSTAR score was significantly correlated with language restriction (beta =-1.31, 95% confidence interval [CI]: -2.62, -0.01, P=0.05) and author contact for missing data (beta =2.16, 95% CI: 0.91, 3.41, P=0.001). However, after adjusting for compliance with reporting guidelines, language restriction was no longer significantly associated with the AMSTAR score.Conclusion: Fewer than half of the SRs conducted to support the clinical practice guidelines we examined reported contacting study authors or searched non–English literature. SRs that did not conduct these two steps had lower quality scores, suggesting the importance of these two steps for overall SR credibility.Keywords: evidence-based medicine, research design, validity, quality of evidenc
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