1,720,953 research outputs found
Thermal characterisation of the furnace tap floor environment of a platinum group metals smelter
Full text linkMaster of Health Sciences in Occupational Hygiene, North-West University, Potchefstroom CampusBackground: South Africa is the leading global producer of platinum group metals (PGMs), a vital industry that relies on high-temperature smelting processes. The smelting of PGM ore occurs in furnaces operating at extreme temperatures of 1350–1600°C, which generate significant radiant heat. Molten materials, released from the furnace during furnace tapping, pose an additional source of radiant heat. This intense thermal environment creates substantial risks of heat stress for workers performing tasks on the furnace tap floors. Despite the critical role these areas play in smelting operations, the thermal environment of furnace tap floors at PGM smelters remains poorly characterised. Understanding these conditions is essential for improving worker safety and informing the design of effective protective equipment. Objectives: To quantify various environmental variables (heat flux, dry-bulb temperature [DBT], wet-bulb temperature [WBT], globe temperature [GT], relative humidity [RH], wet-bulb globe temperature [WBGT] and air velocity) on the matte and slag tap floors, to assess and compare the spatial variation of the thermal variables within and across the tap floors, and to compare the heat flux and WBGT values to reference values. Method: Environmental variables were measured across a grid on the matte and slag tap floors at a PGM smelter during normal tapping conditions. Environmental monitoring instruments, including heat stress monitors and a thermal comfort measurement system, were used to quantify heat flux, DBT, WBT, GT, RH and indoor wet-bulb globe temperature (WBGTi) on the tap floors. Contour maps of the thermal variables were generated using Surfer® software to assess spatial variations. Observations were made regarding the tappers’ duration of presence in various locations, activity levels and clothing. This information was used to estimate the time-weighted average effective WBGT (TWA-WBGTeff) values according to the ISO 7243 standard for various exposure scenarios. Heat flux exposure at various locations was estimated and compared to the recommended maximum durations for aluminised clothing. Results: The following mean levels of thermal variables were measured on the slag tap floor: 35.6 ± 3.6°C (DBT), 22.1 ± 1.9°C (WBT), 50 ± 10.4°C (GT), 16.2 ± 5.5% (RH), 29 ± 3.7°C (indoor wet-bulb globe temperature [WBGTi]) and 974 ± 537 W/m² (heat flux). The matte tap floor exhibited the following levels of these variables: 35.8 ± 3.1°C (DBT), 20.8 ± 1.8°C (WBT), 48.5 ± 9.2°C (GT), 11.1 ± 2.3% (RH), 27.8 ± 3.2°C (WBGTi) and 554 ± 458 W/m2 (heat flux). Hotspots on the matte tap floor were observed surrounding the active tap-hole and launder, whereas the slag tap floor exhibited a hotspot at the centre front and cooler regions at the sides. A moderate to strong and statistically significant correlation was observed between WBGT and heat flux on both the matte (rs(15) = 0.68, p = 0.006) and slag tap floors (rs(19) = 0.67, p = 0.002). The TWA-WBGTeff exceeded their respective limits in all scenarios except when only 20 minutes per hour was spent on the tap floors. The heat flux levels at various locations (< 4600 W/m2) did not exceed the exposure durations since no maximum exposure duration is recommended at this heat flux level. Conclusion: The matte and slag tap floors present distinct and non-uniform thermal environments with spatially varying conditions. On the matte tap floor, heat is concentrated around the active launder while the slag tap floor presents a more balanced thermal environment, reflecting the difference in tapping practices between the floors. The correlation between heat flux and WBGT suggests future research regarding its potential as a proxy for conventional heat stress metrics. Elevated thermal conditions are present on the tap floors that pose a risk of heat stress to furnace tappers depending on location and exposure duration. More than 20 minutes per hour on the tap floor when wearing an aluminised suit poses a risk of heat stress to furnace tappers. These findings could inform future workplace interventions by identifying high-risk areas and understanding the factors contributing to heat stress, enabling more targeted and effective strategies to protect furnace tappers.Master
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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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