1,721,028 research outputs found
Surface and Groundwater Quality in South African Area—Analysis of the Most Critical Pollutants for Drinking Purposes
No full textAccording to a recent report by World Health Organization, the countries which still have limited access to water for drinking purposes are mainly those in the Sub-Saharan region. (Potential) water sources for drinking needs may contain different contaminants. In this context, the current study consists in an overview of the quality of surface water and groundwater in the Republic of South Africa (RSA) and Mozambique (MZ) and provides the variability ranges of the concentrations of the main pollutants in the two countries. Chemical and physical characteristics and concentrations of macropollutants, inorganic compounds (metals) and selected microorganisms were collected for surface water and groundwater and compared with the standards for drinking water set in the two countries. It was found that in surface water, microorganisms were always at very high concentrations. In addition, nickel (in RSA) and boron and chlorine (in MZ) were the most critical compounds. It emerged that in groundwater, arsenic, lead and chlorine (in RSA) and boron, sodium and chlorine (in MZ) were the main critical pollutants. Adequate treatments in the construction of new drinking water plants in rural areas should be selected on the basis of these most critical compounds and their observed variability over time
A New Alternative for Flocculation with Moringa Oleifera in Ecuador
No full textEven though Ecuador is a country with one of the highest concentration of rivers per square kilometer, its water resources are of poor quality d there is a lack of drinking water and sewage systems for its population. In 2013, only 34% of the rural population had access to drinking water and 25% to sewerage services. This is because of a lack of infrastructure and the necessary budgets allocated to them. This paper deals with a proposal for water purification that consists of the use of the Moringa olifeira plant to facilitate the flocculation process, considering that its use reduces the costs associated with the water treatment and minimizes the concentration of metals in the residual sludge. The dosage effects of the plant seeds during the flocculation processes were explored with Jar tests using a solution in doses from 250 to 350 mg per liter of water and then evaluating Chemical Oxygen Demand (COD) and turbidity as selected response variables. The COD reduction goes from the 45% to 55% while the turbidity reduction goes from the 77% to 81%, making the use of the plant possible and feasible
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
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