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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
Comportamento geotécnico de estéril de bauxita e seu potencial uso como extrato de fundação
Get PDFDissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2019.O alumínio é o terceiro elemento em abundância na crosta terrestre, sendo um dos principais
minerais extraídos na região norte do Brasil. O processo de produção do alumínio tem início na
extração da bauxita, comumente feita pelo método de lavra em tiras, por meio do decapeamento
e empilhamento da camada de solo acima deste minério, conhecida como estéril. Essa camada
denominada argila Belterra, ou argila amarela, pode variar de 20 cm a 14 m, com horizontes
médios de 10 m, sendo que as pilhas de estéril de bauxita podem chegar a até 20 m de altura.
Estudos do comportamento geotécnico desse tipo de material, bem como dos solos tropicais da
região norte do Brasil, são limitados na literatura. Sendo assim, este trabalho buscou avaliar os
resultados de campanhas de investigação geológico-geotécnica feitas em regiões de pilha de
estéril de bauxita e de aterro compactado formado por este material, de modo a caracterizar o
solo, estudar o efeito da compactação nas propriedades do material, avaliar o comportamento
do mesmo durante o cisalhamento não drenado e comparar resultados de ensaios de campo e
laboratório. Foram analisados ensaios de Sondagem a Percussão (SPT), Cone (CPT), Piezocone
(CPTU), Palheta (Vane Test), Triaxial CIU, Adensamento, Caracterização e Compactação. Os
principais resultados obtidos mostraram que o estéril de bauxita pode ser classificado como um
material fino, silto-argiloso de alta plasticidade. Em estado solto, como pilha, quando saturado
e em condição não drenada, apresenta significativa geração de poropressões durante o
cisalhamento, mostrando incialmente tendência à contração até alcançar um estado de
transformação de fase, a partir do qual se inicia uma tendência à dilatação. Quando compactado,
mostrou, em geral, tendência à dilatação durante cisalhamento não drenado, justificando uma
análise de estabilidade em termos de tensões efetivas. Em complemento, foram feitas
simulações numéricas no software PLAXIS 3D, considerando a execução de uma fundação em
radier estaqueado assente sobre aterro composto de estéril de bauxita, considerando o
carregamento equivalente ao peso de um tanque de água, de modo a avaliar deformações
geradas. A modelagem numérica considerou três espessuras de radier, simulando uma condição
rígida, semi flexível e flexível, para quatro configurações de estacas com esbeltezes distintas.
Para atendimento ao critério de máximo recalque total admissível, considerando a carga de
projeto estabelecida, a configuração de radier flexível, com L/D=40, foi a que apresentou
melhores resultados. O estéril de bauxita se mostrou competente como aterro para alguns
carregamentos simulados.Aluminum is the third element in abundance in the earth's crust, being one of the main minerals
extracted in the northern region of Brazil. The aluminum production process begins with the
extraction of bauxite, using the strip-mining method, by stripping and stacking the soil layer
above the ore, known as overburden. This layer called Belterra clay, or yellow clay, can vary
from 20 cm to 14 m, with average horizons of 10 m, and the bauxite overburden piles can reach
up to 20 m in height. Studies of the geotechnical behavior of this material, as well as the tropical
soils of northern Brazil, are limited in the literature. Thus, this work aimed to evaluate the
results of geological and geotechnical investigation carried out in bauxite overburden piles
areas, in order to characterize the soil type, study the effect of compaction on the material
properties, evaluate its behavior during undrained shear and compare results of field and
laboratory tests. Standard Penetration Tests (SPT), Cone Penetration Tests (CPT), Piezocone
Penetration Tests (CPTU), Vane Test, Triaxial CIU, Consolidation, Characterization and
Compaction tests were analyzed. The main results obtained showed that bauxite overburden
can be classified as a thin, silty clayey material with high plasticity. In a loose condition, as an
overburden pile, when saturated and in an undrained condition, it presents significant generation
of pore pressure during shear, initially showing a tendency to contraction until reaching a phase
transformation state, from which a tendency to dilatation begins. When compacted, it generally
showed a tendency to dilatation during undrained shear, justifying a stability analysis in terms
of effective stresses. In addition, numerical simulations were performed in the PLAXIS 3D
software, considering the execution of a piled raft foundation over a bauxite overburden pile
layer, considering a loading equivalent to the weight of a water tank, in order to evaluate the
generated deformations. The numerical modeling considered three raft thicknesses, simulating
a rigid, semi flexible and flexible condition, for four configurations of distinct piles. In order to
attend the maximum allowable settlement, considering the established design load, the flexible
piled raft configuration with L/D = 40 presented greatest results. It was concluded that the
bauxite overburden is competent as a foundation layer for some simulated loads.Faculdade de Tecnologia (FT)Departamento de Engenharia Civil e Ambiental (FT ENC)Programa de Pós-Graduação em Geotecni
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
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
Assessment of the behavior of soil-structure foundation elements like piled footing
No full textEste trabalho visa estudar o comportamento e a interação entre solo, sapata e estaca, baseado na execução e monitoramento de quatro provas de carga direta executadas em: uma sapata isolada, uma sapata com uma estaca, uma sapata com quatro estacas e uma estaca isolada. Durante as provas de carga, os deslocamentos verticais em diferentes profundidades, correspondentes aos diferentes bulbos de tensão, foram monitorados, usando uma instrumentação especial que se denominou dispositivos BETAS . Para determinação das características mecânicas do solo residual de gnaisse existente no local das provas de carga, foram executados no campo ensaios de sondagens à percussão (SPT), ensaios dilatométricos planos (DMT) e ensaios pressiométricos de Ménard (PMT). No laboratório, foram realizados ensaios de caracterização e ensaios para a determinação das características de deformabilidade e resistência, em amostras deformadas e indeformadas do solo. Capacidades de carga e recalques admissíveis obtidos no campo foram comparados com os fornecidos por metodologias teóricas e empíricas baseadas em ensaios de campo e de laboratório, para avaliar a validade destas metodologias. Além disso, usando-se o método dos elementos finitos por meio do programa comercial Abaqus, foram feitas comparações entre as curvas carga-recalque obtidas numericamente e nas provas-de-carga e, por fim, um estudo paramétrico foi realizado para verificar a influência do número de estacas no comportamento da sapata.This work aims to study the behavior and interaction between soil, shallow footing and pile, based on the implementation and monitoring of four direct load tests performed on: a single shallow footing, a shallow footing with one pile, a shallow footing with four piles and a pile alone. During the load tests, vertical displacements were monitored at different depths, corresponding to different stress bulbs, using a special instrumentation which was called "BETAS devices. To determine the mechanical characteristics of gneiss residual soil, standard penetration tests (SPT), flat dilatometer tests (DMT) and Ménard pressuremeter tests (PMT) were performed in the field. In laboratory, tests were carried out to characterize and to determine the strength and deformability characteristics of the soil, using disturbed and undisturbed samples. Loading capacities and allowable settlements obtained in the field were compared with the ones provided by theoretical and empirical methodologies based on field and laboratory tests, to evaluate the validity of these methodologies. Furthermore, using the finite element method through the commercial software Abaqus, comparisons were made between the load-settlement curves obtained numerically and by the load-tests and, finally, a parametric study was realized to investigate the influence of the number of piles in the behavior of the shallow footing
Analysis of a rigid shallow foundation instrumented load test
No full textO objetivo principal deste trabalho é avaliar as metodologias usualmente utilizadas para prever a capacidade de carga e recalques de fundações rasas rígidas. Para isso foi realizada uma prova de carga durante a qual foram monitorados os deslocamentos verticais em diferentes profundidades, correspondentes aos diferentes bulbos de tensão, usando uma instrumentação especial a qual denominou-se BETAS . Para determinação das características mecânicas do solo residual de gnaisse existente no local da prova de carga foram executados ensaios de penetração (SPT), ensaios dilatométricos de Marchetti (DMT) e ensaios pressiométricos de Ménard (PMT), em solo residual de gnaisse presente no local da prova de carga. No laboratório foram executados ensaios de caracterização e ensaios para a determinação das características de tensãodeformação e resistência, em amostras deformadas e indeformadas do solo. O estudo mostrou que os métodos de campo permitiram a obtenção de bons resultados, para subsolos bastante heterogêneos como os formados por solos residuais.The main objective of this work is to evaluate methodologies usually used to foresee the load capacity and settlements of rigid shallow foundations. A load test was accomplished, during which, vertical displacements were monitored in different depths, corresponding to different stress bulbs, using a special instrumentation, called "BETAS". To determine the mechanical characteristics of the gneiss residual soil existing in the place where the load test was realized, penetration tests (SPT), Marchetti dilatometer tests (DMT) and Ménard pressiometer tests (PMT) were executed. In the laboratory, characterization tests and tests to determine the stress-strain-strength characteristics were executed with disturbed and undisturbed samples of the soil. The study showed that the field methods allowed to obtain good results, even for heterogeneous undergrounds as the ones formed by residual soils
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