1,720,953 research outputs found
Evaluating radiological impacts due to uranium mining in the Erongo Region, Namibia
Full text linkDSc (Science with Radiation Science), North-West University, Mahikeng CampusThe unambiguous and continuously increasing exposures of human beings to terrestrial radiations is highly attributed to naturally occurring radioactive materials in the environments. Background radiation had been increasing gradually due to mining and milling activities worldwide to acquire nuclear materials needed for a response to electrical demands globally. The most significant health effects associated with the continued exposure to NORMs are lung cancer and leukemia. The main aim of this study was to evaluate the radiological risks associated with naturally occurring radioactive materials from uranium mining activities to critical groups in Erongo Region, Namibia. The study analyzed the radiological emissions of gamma rays in soil samples using high-purity germanium detector and determined the elemental and radiological concentrations in dust and water using inductively coupled plasma-mass spectrometry Equipment. The target radionuclides were 238U, 226Ra, 232Th and 40K. The weighted mean values of activity concentrations with standard deviations measured for 238U, 226Ra, 232Th and 40K in soil samples using high-purity germanium detector ranged between 104.77±5.23 and 4610.29±50.57 Bq.kg-1, 42.22±0.73 and 4909.40±18.13 Bq.kg-1, 91.02±1.09 and 436.74±5.16 Bq.kg-1, and 683.06±12.88 and 2225.00±52.65 Bq.kg-1, respectively. All activity concentrations calculated were found to be significantly higher than the world averages levels of 35, 33, 45 and 420 Bq.kg-1, respectively reported by United Nations Scientific Committee on the Effects of Atomic Radiation. Khan river was the only section of study with low radioactivity level. Mean values with standard deviation only for absorbed dose , radium equivalent, annual effective dose, internal and external hazard indices were ranging between 135.89±2.58 to 2290.70±23.53 nGy.h-1, 253.45±2.03 to 5271.51±19.28 Bq.kg-1 and 0.83± to 14.05± mSv.y-1, 0.86±0.01 to 27.51±0.01 and 0.68±0.01 to 14.25±0.01, respectively. Gamma and alpha indices were calculated ranging from 0.93±0.01 to 17.69±0.07, and 0.21±0.01 to 24.55±0.09, respectively. The probability of cancer development in a biological body was estimated by a human health related hazard known as excess lifetime cancer risk. The calculated cancer risks were ranging from 2.92x10-3 to 4.99x10-2 for the soil samples, values which were significantly higher than both the world average (0.29x10-3) and limit (1.45x10-3) documented by United
Nations Scientific Committee on the Effects of Atomic Radiation and International Commission on Radiation Protection, respectively.
The elemental and activity concentrations for naturally occurring radioactive materials were also determined using inductively coupled plasma-mass spectrometry. The mean values in water from the tailings and boreholes were 17.18 and 3.17 Bq.l-1 for 238U, 1.72 and 0.024 Bq.l-1 for 232Th and 12.40 and 11.58 Bq.l-1 for 40K, respectively. These calculated radioactivity concentration values exceeded the drinking water quality guidelines levels recommended by World Health Organization for gross alpha screening and gross beta levels of 0.5 mBq.l-1 and 1.0 mBq.l-1, respectively.
The results show that both tailings and borehole water were unsuitable for human consumption and therefore, contact with edible food must be avoided by all means. For the dust from mine 2, the average activity concentrations were 80.94 Bq.l-1 for 238U, 673.12 Bq.l-1 for 232Th and 27.95 Bq.l-1 for 40K. The results had shown high transferrable probability of thorium radionuclide in the atmosphere than uranium and potassium nuclides. In dust, 232Th was recorded with significant high value of radioactivity concentration at 673.12 Bq.l-1, which was higher than the world average level of 45 Bq.kg-1, documented by United Nations Scientific Committee on the Effects of Atomic Radiations.
On excess life cancer risks, the RESRAD-OFFSITE model 4.0 was used with ICRP 107 based radionuclide transformations transfer factors and ICRP 60 external, inhalation and ingestion dose conversion factors to perform the analysis. The cancer morbidity risks modelled for naturally occurring radioactive materials in both mines’ samples had shown that 226Ra was the highest contributor. The RESRAD modelling was performed on water, plants, soil and atmospheric exposure pathways by external gamma, inhalations and ingestions and had shown risk factors in descending order as 226Ra ˃ 232Th ˃ 40K ˃ 238U. In RESRAD-OFFSITE model code, the total cancer morbidity risks were recorded with about 3 persons per 1 000 populations (3 x 10-3) by tailings soil (stockpiles) and surrounding soil samples of mine 1 less than 7 to 8 persons per 1 000 populations (7 x 10-3 – 8 x 10-3) by tailings (stockpiles) soil samples in mine 2 less than 7 to 9 persons per 1 000 populations (7 x 10-3 – 9 x 10-3) by uranium ore samples of mine 1 were at risks of
developing cancer. This could explicitly prove that the modelled cancer risks in the region were higher than the recommended level of 1 x 10-5 factor for a population and 1 x 10-3 for a subpopulation documented by the World Health Organization as well as the world average (0.29 x 10-3) documented by the United Nations Scientific Committee on the Effects of Atomic Radiation.Doctora
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
- …
