1,720,958 research outputs found
A hydrotectonic model of a geothermal reservoir - A study in Lahendong, Indonesia
No full textIn this study tectonic structural features and their hydraulic characteristics of fault zones were integrated into a consistent hydrotectonic model of the Lahendong geothermal reservoir, Indonesia. Moreover, these elements were analysed with respect to their relevance for the operation of the geothermal power plant at initial conditions, i.e. before the start of operation. The complex tectonic setting with volcanic activity provides evidence for relevant structural and hydrogeological elements, such as fault zones, surface spring discharge and joints at different spatial scales. The study area is highly variable with respect to hydraulic properties and chemical composition of the fluids. It consists of two types of fluids. Acid brine water with a pH of around 3 and an electrical conductivity ranging between 462011 mu S/cm and 9700 p,S/cm is characteristic for the reservoir in the North with temperatures up to 274 C. A moderate pH between 4 and 7, an electrical conductivity in the range of 400-1730 mu S/cm and temperatures of up to 340 C characterise the southern study area. The Lahendong geothermal field is subdivided into two sub-reservoirs. Faults are less permeable perpendicular to the strike of the faults than parallel to the strike. The characteristics of the complex reservoir system could be explained by the combination of hydrotectonics and hydrogeological parameters. Understanding the permeability distribution along fault zones is crucial to investigate subsurface fluid pathways as well as to sustainably use the reservoir. A compartmentalisation of the reservoir was derived from a stress field analysis of the tectonic elements and from hydrogeological observations. The information on underground fluid flow is essential to understand the subsurface flow of geothermal fluids. Here, the permeability of structures is identified as the limiting factor. (C) 2014 Elsevier Ltd. All rights reserved.German Federal Ministry for Education and Research (BMBF) [03G0753A
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
Permeability distribution in the Lahendong geothermal field: A blind fault captured by thermal–hydraulic simulation
No full textSubsurface fluid flow of reservoirs in active tectonic regions is mainly controlled by permeability of fault zones. Therefore, the characterization of fault zones is an important step toward performance assessment of a reservoir. The fluid flow is controlled also by pressure and temperature conditions. In this context, we simulated pressure and temperature fields to elaborate on the influence of permeability on subsurface fluid flow in the Lahendong geothermal reservoir. Thermal-hydraulic simulation is performed using a finite element approach. Adjusting the permeability through 370 different cases, modeling results converged to the observed data within a misfit range of 0-7 %. The best fitting models identified a deep-seated fault that has previously not been traced at the surface. Simulated temperature distribution suggests a prominent convective heat flow, driven by an upward migrating and SW-NE oriented fluid flow. This hydraulic gradient causes a pressure drop along the reservoir. High-pressure patterns are used to constrain recharge areas, in addition to infiltration measurements. Discharge flow occurs from SW to NE migrating also upward toward the hot springs. In that frame, thermal-hydraulic simulations identified previously unresolved subsurface faults, which now allow a better understanding of the subsurface permeability and its influence on fluid flow.German Federal Ministry for Education and Research (BMBF) [03G0753A
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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