1,721,005 research outputs found
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
Estudio de la precipitación de los elementos de tierras raras con ácido oxálico en un sistema de agua ácida de mina influenciada por metales
No full textDesde el siglo XX, las tierras raras (REE) se han posicionado como materias decisivas para el avance tecnológico
con el objetivo de implementar esquemas circulares y valorizar los residuos. Pero el acceso a una fuente confiable
de REE para la Unión Europea supone un desafío debido a la falta de minas, lo que conlleva a una relación de
dependencia con China. El país oriental tiene la mayor producción y reserves de REE en el mundo siendo el
principal exportar a nivel global. Actualmente, la UE investiga y estudia recursos secundarios de suministro
sostenible, como son las aguas ácidas de mina (AMW de sus siglas en inglés).
El abandono de las explotaciones mineras favorece la formación de las AMW mediante la oxidación de sulfuros
metálicos en presencia del oxígeno y la humedad atmosférica, dando lugar a la formación de ácido sulfúrico,
metales de transición y REE. Estos drenajes resultan tóxicos para el hombre, la fauna y la vegetación, pero a su vez
se ha identificado como singularidad la presencia de REE en concentraciones que plantean la posibilidad de
convertirse en una fuente secundaria.
Este Trabajo de Final de Grado se ha centrado en el estudio de un tren de tratamiento de AMW que permita su
recuperación mediante precipitación selectiva con H2C2O4. En etapas previas no incluidas en el alcance de este
TFG, las REE son extraídas y concentradas mediante intercambio iónico. La regeneración de las resinas de
intercambio iónico con H2SO4 0,4M, genera unas disoluciones de REE de la cuales el objetivo perseguido es su
recuperación en forma de oxalatos de REE. El objetivo de este estudio es identificar las dos condiciones más
importantes de operación: pH y concentración de H2C2O4necesaria para conseguir la máxima recuperación de las
REE, evitando la presencia de otros elementos alcalinotérreos de transición y post-transición para conseguir la
mayor pureza de los oxalatos precipitados en REE.
Para ello, se han evaluado diferentes condiciones experimentales: i) a diferentes valores de pH que se encuentran
en el rango de 0,5-3,0, ii) con diferentes métodos de adición de H2C2O4: adición directa y adición con bomba
peristáltica, iii) a diferentes relaciones estequiométricas que influyen en el volumen a dosificar de H2C2O4. El
trabajo experimental se ha realizado utilizando disoluciones sintéticas que simulan las condiciones esperadas en
las disoluciones en ácido sulfúrico generadas en la regeneración de las resinas de intercambio iónico.Since the 20th century, rare earths (REE) have been positioned as decisive materials for technological
advancement with the aim of implementing circular schemes and valorizing waste. But access to a reliable REE
source for the European Union is a challenge due to the lack of mines, leading to a dependency relationship with
China. The eastern country has the largest production and reserves of REE in the world being the main export
globally. The EU is currently researching and studying sustainable secondary supply resources, such as acidic mine
water (AMW).
The abandonment of mining operations favors the formation of AMW by oxidation of metal sulfides in the
presence of oxygen and atmospheric humidity, leading to the formation of sulphuric acid, transition metals and
REE. These drains are toxic to man, fauna and vegetation, but the presence of REE in concentrations that pose the
possibility of becoming a secondary source has been identified as a singularity.
This Final Grade Study focused on the study of an AMW treatment train that allows its recovery by selective
precipitation with H2C2O4. In previous stages not included in the scope of this work, REE are extracted and
concentrated by ion exchange. The regeneration of ion exchange resins with H2SO4 0,4M generates REE solutions
from which the objective is their recovery in the form of REE oxalates. The objective of this study is to identify the
two most important operating conditions: pH and oxalic acid concentration necessary to achieve maximum
recovery of REE, avoiding the presence of other alkaline elements transition and post-transition to achieve the
highest purity of REE precipitated oxalates.
For this purpose, different conditions have been evaluated with different experimental conditions: i) at different
pH values found in the range of 0.5-3.0, ii) with different methods of adding H2C2O4: direct addition and addition
with peristaltic pump, iii) to different stoichiometric ratios that influence the dosing volume of H2C2O4. The
experimental work has been carried out using synthetic solutions that simulate the expected conditions in the
sulfuric acid solutions generated in the regeneration of ion exchange resins
Evaluación de tecnologías de membranas para la separación y recuperación de amoníaco en corrientes líquidas
Full text linkAquest TFG aborda l'anàlisi exhaustiva de les tecnologies de membranes utilitzades per a la separació i recuperació d'amoni de corrents líquids, un contaminant comú en residus industrials i municipals que pot afectar significativament la qualitat de l'aigua i que és a més una matèria primera.
Es revisen tres tecnologies de membrana: la destil·lació per membrana (MD), els contactors de membrana (MC) i la pervaporación (PV). Cadascuna d'aquestes tecnologies s'avalua en funció de les seves característiques morfològiques i estructurals, com el material de la membrana, la grandària dels porus i el gruix.
Els paràmetres operatius, com per exemple la temperatura, el pH, el cabal o la concentració de l'alimentació són factors que determinen el rendiment de la membrana.
A través d'una revisió bibliogràfica i l'anàlisi de deu estudis experimentals publicats, es comparen les eficiències d'aquestes tecnologies en la recuperació d'amoni.Este TFG aborda el análisis exhaustivo de las tecnologías de membranas utilizadas para la separación y recuperación de amonio de corrientes líquidas, un contaminante común en residuos industriales y municipales que puede afectar significativamente a la calidad del agua y que es además una materia prima.
Se revisan tres tecnologías de membrana: la destilación por membrana (MD), los contactores de membrana (MC) y la pervaporación (PV). Cada una de estas tecnologías se evalúa en función de sus características morfológicas y estructurales, como el material de la membrana, el tamaño de los poros y el espesor.
Los parámetros operativos, como por ejemplo la temperatura, el pH, el caudal o la concentración de la alimentación son factores que determinan el rendimiento de la membrana.
A través de una revisión bibliográfica y el análisis de diez estudios experimentales publicados, se comparan las eficiencias de estas tecnologías en la recuperación de amonio.This TFG deals with the comprehensive analysis of membrane technologies used for the separation and recovery of ammonium from liquid streams, a common contaminant in industrial and municipal waste that can significantly affect water quality and is also a raw material.
Three membrane technologies are reviewed: membrane distillation (MD), membrane contactors (MC) and pervaporation (PV). Each of these technologies is evaluated in terms of its morphological and structural characteristics, such as membrane material, pore size and thickness.
Operational parameters such as temperature, pH, flow rate or feed concentration are factors that determine membrane performance.
Through a literature review and the analysis of ten published experimental studies, the efficiencies of these technologies in ammonium recovery are compared
Efecto de los iones contaminantes presentes en aguas ácidas de mina en la precipitación de tierras raras mediante ácido oxálico
No full text- …
