1,720,956 research outputs found
The Analysis and Remediation of Excess Fluoride in Drinking Water in Isle of Wight County, VA
Get PDFExcess fluoride in drinking water can cause fluorosis or brown and yellow staining of the enamel of teeth. In extreme cases, severe damage to teeth and bone structure can develop. In 1993, the World Health Organization set a limit of 1.5 ppm as acceptable for drinking water; however, in Isle of Wight County, Virginia, recent water quality reports detected levels of fluoride as high as 4 ppm. The purpose of this study was to investigate several detection and remediation methods of fluoride in drinking water. Detection methods included an ion selective electrode (ISE), dye-based colorimetric methods, and an at-home testing kit. ISE is the standard method for fluoride analysis. Remediation methods included commercially available activated alumina, charcoal, and water pitcher filters. Water samples were collected from locations using both wells and municipal water throughout Isle of Wight County, Virginia. Currently, parts of the county are under an advisory for fluoride levels. The water samples tested contained fluoride ranging from 1 to 6 ppm. Of the detection methods used, ISE and colorimetric methods proved to be more accurate than an at-home test kit, which indicated that all samples contained a fluoride concentration less than 0.50 ppm. The ultimate goal of this study was to develop a cost-effective method to detect and remove fluoride from drinking water in rural communities without water treatment facilities. Educational materials will be developed to help residents in these communities understand and manage their water quality
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
The Analysis of Heavy Metals in Samples of Honey using X-Ray Fluorescence and Anodic Stripping Voltammetry
Get PDFA daunting reality is haunting scientists as Colony Collapse Disorder (CCD) is declining bee population in the United States (1). A concrete conclusion as to why CCD is happening remains unclear but extensive research and studies are leaning towards a toxic component in honey to bees called hydroxymethylfurfural (HMF) (1). HMF has been a culprit in question for a while but researchers are still on the fence as to whether it should be concluded as such. It is theorized that HMF is formed in very warm temperatures and catalyzed by a metal in honey; manganese (1). Manganese is one of the many heavy metal elements in honey but is under suspicion that it creates HMF in honey in such magnitude that it kills off the bees who part take in it. In this study, a honey sample was put under various conditions to investigate the presence of heavy metals in honey. Some of the main metals of interest for this study were Mn, Fe, and Zn. It was found that Mn in the honey which was x=2.45ugMn/ghoney, Fe in the honey was found to be x=2.72ugFe/ghoney, and Zn in the honey was found to be x=.95ugZn/ghoney
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
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