1,721,064 research outputs found
Fluid Circulation in Coupled Free and Porous Domain: Implications of Porous Media Heterogeneity
No full textFluid flow in coupled free and porous domain, particularly when the porous medium is
heterogeneous, is encountered in many hydro-environmental conditions. These include,
e.g., groundwater hydrology, conjunctive surface and subsurface flow, mud cake
formation during drilling of oil wells and others. One of the most difficult
problems in the study of coupled flow behaviour has been the development of a
universally applicable modelling scheme for combining the flow regimes. This is
because the free/porous interfacial properties (e.g., shear-stress; velocity slip)
that determine the coupled flow behaviour are difficult to determine experimentally.
On the other hand, the implications of various forms of heterogeneity in the porous
media properties can be very different on the fluid flow behaviour. Difficulties may
also arise in coupling the model equations (e.g., Navier-Stokes for free flow region
and the Darcy Equation for the porous flow region) that govern the fluid flow in the
individual regions. Consequently, models of coupled free and porous flow for hydro-
environmental conditions are not very well developed at the moment.
Our previous work suggests that fluid in the porous section may circulate because of
complex (variable) pressure distributions in the domain. In this paper, we aim to
analyse how porous media heterogeneity affects the flow circulation in the porous
section of a coupled free and porous domain and subsequently the overall flow
behaviour. For this purpose, we analyse flow patterns for several different domains
made up of two porous layers with differing permeabilities. The governing model
equations are discretised and solved using the standard finite volume method on a
staggered (cell centred) mesh. The temporal discretisation is done using the
implicit method. An in-house graphical user interface (GUI) has also been created
specifically to aid in the visualisation of otherwise complex flow patterns. The GUI
contains many plot (post processing) options that provide a comprehensive tool for
the analysis of hydrodynamics and contaminant motion (not discussed in this paper)
in coupled free and porous flow domains. The effects of altering the aspect ratio
of the domain on the coupled flow pattern have also been analysed. This paper
promises to bring a new dimension to the existing knowledge on coupled free and
porous flow behaviour.Presenters:
name: Das, Diganta
affiliation: Oxford Universit
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
Solving Challenging Problems in the Oil Industry Using Artificial Intelligence Based Tools
Full text linkPredictive modelling is a process used in predictive
analytics to create a statistical model of future behaviour.
Predictive analytics is the area of data mining concerned
with forecasting probabilities and trends. On the other hand,
Artificial Intelligence (AI) concerns itself with intelligent
behaviour, i.e. the things that make us seem intelligent.
Following this process of thinking, in this work we have as
the main goal the assessment of the impact of using AI
based tools for the development of intelligent predictive
models, in particular those that may be used to classify
industrial waste, such as the residual waters in a refinery,
based on the type of the mixtures of crude oil that arrive
into the site to be processed.
Indeed, these models will enable the prediction of the
quality classes of the effluents that will be disposed, in
order to assure that Industrial Residual Water does not
affect negatively the ecology of the receptors or the Staff
Health and Safety and obeys the current legislation. The
software employed was Clementine 11.1 and C5.0
Algorithm was used to induce decisions trees. The data in
the database was collected from 2006 to 2007, and includes
production data and effluent analysis data
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
Mass transfer analysis of transdermal drug delivery using microneedles
Full text linkMicroneedle is a promising technique for delivering high molecular weight drugs across skin. The microneedles can offer a number of benefits over other drug delivery methods. For example, the drugs only diffuse over a short distance before reaching the blood circulation which enhances the absorption of drugs by the tissue. However, the drug transport behaviour in skin is affected by a complex interplay of many parameters (e.g., microneedle geometries, permeability across skin, etc).In this thesis, many aspects of the microneedle field were examined. A mathematical model for drug transport from microneedle systems into skin was developed. Issues such as microneedle penetration, surface area of the microneedle arrays, etc. were investigated. This work helped us to focus into optimizing the design of microneedles by developing an in-house algorithm to enhance the performance of transdermal drug delivery using microneedles. Following the development of this algorithm, the influence of skin thickness with its classification (i.e., age group, race, etc.) on drug permeability across skin was studied. Attention was then given to determine the effective permeability (Peff) and the effective skin thickness (Heff) for various solid microneedle models. The outcome of this research allowed us to study the influence of microneedle dimensions on the drug concentration in blood (Cb). Furthermore, the 'pattern' (shape) of the microneedles array (i.e., square or rectangular) and the 'distribution' (arrangement) of the microneedles inside an array (i.e., triangular or diamond) were investigated to identify the optimum microneedle models. Finally, the effect of skin metabolism on both the patch (without microneedles) and the microneedle arrays on drug intake were examined
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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