1,720,968 research outputs found
Jet mixing of water in crude oil pipelines
Get PDFThe jet mixing of water in crude oil pipelines by single nozzle and
multi-nozzle mixers was studied by dividing the mixing domain into to
three regions. the penetration. near field and farfield regions. At
the penetration region the quantitative experimental data were aided
by a flow visualisation study in an attempt to to form fundamental
semi-empirical correlations to estimate the entrainment rate of
stratified water from the bottom and the Sauter mean diameter of
the entrained water droplets for a single nozzle jet mixer.
The flow field diagnostics into the near field region. defined as the
region where high level of swirl and mixing is occuring. were
conducted theoretically using computational fluid dynamic code
"Phoenics" and experimentally through LOA measurements and flow
visualisation. The entrainment rate found in penetration region was
treated as a source term for theoretical analysis.
Experimental analysis of this region was conducted in single phase
flow for two mixer nozzles i) Single nozzle mixer and ii). Existing
multi-nozzle mixer. Experimental results have revealed that the swirl
velocities decay faster for higher velocity ratios and their
dependence on Reynolds number (in the range 27600 to 48400) is weak.
Higher velocity ratios would generate and dissipate higher levels of
energy, therefore break up water droplets to smaller sizes and
increase the eddy viscosity. The dispersion strength due to swirl
decays faster and the gravity settling begins earlier.
As the flow reaches downstream. approximately four diameters. the
distribution of velocities (mean and RMS) flattens out and their
magnitude begins to close up for the two mixers. when their momentum
ratios are equal.
It
was also shown that the swirl velocities (at
axis) die away. approximately at the same axial point for both of the
nozzles. The multi-nozzle mixer is shown to be better in two
characteristics; i). The mixing is faster and ii) The jet energy is
more evenly distributed in the vicinity of the injection cross
section. hence improving the quality of the droplet size distribution.
Besides providing information to aid understanding of the complex flow
in the mixer zone. the experimental data is believed to be of
sufficient quality and quantity to improve the present simple
modelling procedures as well as to be used as test cases for
assessment of the predictive accuracy of more elaborate computational
models.
Comparision with computational results (of low velocity ratios) shows
the agreement with swirl velocities is reasonable. but not always
acceptable for mean axial velocities. However. the computational model
predicts the near field jet trajectory reasonably well. The flow
visualisation of dispersion of passive contaminant agrees
qualitatively with the contours of the passive contaminant.
In the far field region. where the swirl has decayed. the flow behaves
two dimensionally. Therefore. an exact solution was obtained for two
dimensional water conservation equation. The boundary conditions were
specified by using sticking probability constants. A relationship was
obtained to specify eddy viscosity through turbulent kinetic energy.
The turbulent kinetic energy and swirl decay were estimated from LDA
experimental data. This solution can be used to study the developing
characteristics of water concentration profiles along the far field
region of the pipeline
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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