1,720,954 research outputs found
The Hydrogeology and Hydrochemistry of the Mt. Tom Price Mine, Pilbara, Western Australia – A Groundwater Flow Model.
Full text linkThe Mt. Tom Price Mine, located in the Pilbara region of Western Australia, has been the site of major iron ore mining since the 1960s by Rio Tinto Iron Ore/Pilbara Iron. The thesis project area covers approximately 121 km², covering the Mt. Tom Price Mining area and the surrounding catchment boundary. The climate in the Pilbara region is arid, with rainfall driven by seasonal cyclonic events, producing 300 mm/year net rainfall on average. The geology of the Mt. Tom Price area consists of a series of banded iron formations (BIF) and shales that are generally low in hydraulic conductivity values. Iron ore in the region is produced through the process of supergene enrichment whereby gangue minerals are dissolved and replaced with haematite and goethite. Mining is focused in a series of open cast pits including, North Deposit, West Pits, Centre Pits, Southern Ridge, South East Prongs, Section Six, Section Seven, and the proposed Marra Mamba Pits. Due to the impermeable nature and complex geology of the BIF sequence, groundwater flow is dominated by bedrock aquifer flow, with compartmentalization occurring in several areas of the mine. Highly faulted and folded units can also have increased hydraulic conductivity values. Pit floor lowering began to encounter the regional water table in early 1994. A series of dewatering bores and depressurization measurements have been utilized to ensure dry mining practice. This data was used to help understand regional groundwater flow and create the Mt. Tom Price Groundwater Model (MTPGM). A 3D geological model of the project area was created to aid visualisation of semi-regional hydrogeology. From this model, accurate template files were created so that geological detail loss is kept to a minimal when entering hydrogeological parameters into the MTPGM. The MTPGM was setup using PMWIN Pro, a graphical user interface for use with MODFLOW. Stresses such as recharge and pumping were entered via software packages within MODFLOW. The model was run to simulate measured 1994-2007 responses to dewatering and high rainfall events. A Parameter Estimation (PEST) software package and trial and error calibration was used to lower stress response variances that were observed in the model output files. This was achieved by the adjustment of hydrogeological parameters such as hydraulic conductivity and specific yield values. A prediction simulation of final pit lake recovery was created Using the calibrated MTPGM. Recovery curves predicted that full recovery of the water table of the pit voids varied from 96 to 120 years, recovering to levels close to the initial heads measured in 1994 before large-scale pumping commenced. The hydrochemistry of the groundwater in the mining area is highly influenced by geological hosts, with clearly defined hydrochemical signatures approximated for each screened geological unit. Due to the sulphur rich, acid- forming Mt. McRae Shale, regular monitoring of pit and groundwater is essential. Final pit lake water quality was estimated using final pit levels and recovery rates approximated from the MTPGM, combined with historical data and previous groundwater quality reports. Pit lake water quality is dominantly driven by evaporation concentration, caused by high evaporation rates and low throughflow. Pit waters are expected to be brine waters (greater than 100,000 mg/L TDS), with high levels of acidity values occurring in the South East Prongs and Section Six pits due to the exposure of the acid forming Mt. McRae Shale above the pit lakes at these localities. Future studies should focus on more detailed modelling of the compartmentalised aquifer systems. This would produce much more accurate final pit lake levels. Further study of the Mt. McRae Shale formation and its implications on acidity should also be undertaken. Seasonal fluctuations in lake levels will affect acidity due to the continual re-exposure and oxidation of the Mt. McRae Shale. This could be studied to help understand short term pit lake quality conditions and help to predict long term acidity conditions in the pit lakes
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
Rapid Data Assimilation Using an Appropriately Complex Model: a GMDSI worked example report
Full text linkThe Groundwater Modelling Decision Support Initiative (GMDSI) is an industry-funded and industry-aligned project focused on improving the role that groundwater modelling plays in supporting environmental management and decision-making. This GMDSI report addresses a number of related issues. They include: appropriate model complexity; appropriate parameterisation complexity; efficient model-based assimilation of information-rich data; and linear analysis. The focus of modelling work that is reported herein is BHP’s Orebody 31 (OB31) situated in the Pilbara region of Western Australia. The environs of this mine have been the focus of a number of generations of modelling, some of which is described in the present report. Mining of OB31 commenced in 2016; however data collection and modelling took place for a number of years prior to that
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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