5,945 research outputs found
Flooding and reequilibration of a series of Pittsburgh bed underground coal mines, 1980 to 2015
This study examines the water-level elevation history of selected flooding and flooded underground mines in the Pittsburgh coal basin of SW Pennsylvania from the time of closure until post-flooding pool-level reequilibration. Mines within this mining district developed pools with nearly steady-state groundwater flow within 10 to 50 years after closure. Equilibrated pool levels within each of the mines were controlled by various combinations of spillage to the surface or other mines, pumpage, and barrier leakage. In a study of flooding in the Clarksville, PA area, field water-level observations, mine geometry, barrier hydraulic conductivity, recharge rates, and late-stage storage gains were parameterized to match known pumping rates and develop a fluid mass balance. Vertical infiltration (recharge and leakage) estimates were developed using a depth-dependent model based on the assumption that most vertical infiltration is focused in areas with \u3c75 m of overburden. A MODFLOW simulation of the nearly steady-state flow conditions was calibrated to hydraulic heads in observation wells and to known pumping rates by varying barrier hydraulic conductivity. The calibrated model suggests significant head-driven leakage between adjacent mines, both horizontally through coal barriers and vertically through interburden into an overlying mine. Calibrated barrier hydraulic conductivities were significantly greater than literature values for other mines at similar depths in the region. This suggests that some barriers may be hydraulically compromised by un-mapped entries, horizontal boreholes, or similar features that act to interconnect mines. These model results suggest that post-mining inter-annual equilibrium conditions are amenable to quantitative description using mine maps, sparse observation-well data, accurately-estimated pumping rates, and depth-dependent vertical infiltration estimates. Results are applicable to planning for post-flooding water control schemes, although hydraulic testing may be required to verify model results.;In a second study of a nearby area, three mines were mapped to determine mining type distribution (longwall, etc.) and these mining-type areas assigned typical porosity values based on industry-standard extraction ratios. The porosity estimates were plotted against coal-base elevation contours to model the hypsometric distribution of porosity. Using pumping rates from active operations and these hypsometric porosities, the approximate duration of flooding was estimated for two of the mines; these overestimate the actual (observed) flooding time by 200-275%. On the other hand, mine inflow rates estimated using observed water levels and the porosity model indicate temporal changes in the fluid mass balance for each mine that are consistent with spillage and/or barrier leakage between mines interpreted from water-level hydrographs. Results indicate that accurate prediction of the duration of mine flooding requires explicit consideration of groundwater conditions in adjacent mines and the potential for barrier leakage
Learning masculinities in a Japanese high school rugby club
This paper draws on research conducted on a Tokyo high school rugby club to explore diversity in the masculinities formed through membership in the club. Based on the premise that particular forms of masculinity are expressed and learnt through ways of playing (game style) and the attendant regimes of training, it examines the expression and learning of masculinities at three analytic levels. It identifies a hegemonic, culture-specific form of masculinity operating in Japanese high school rugby, a class-influenced variation of it at the institutional level of the school and, by further tightening its analytic focus, further variation at an individual level. In doing so this paper highlights the ways in which diversity in the masculinities constructed through contact sports can be obfuscated by a reductionist view of there being only one, universal hegemonic patterns of masculinity
How to Evaluate your Question Answering System Every Day and Still Get Real Work Done
In this paper, we report on Qaviar, an experimental automated evaluation
system for question answering applications. The goal of our research was to
find an automatically calculated measure that correlates well with human
judges' assessment of answer correctness in the context of question answering
tasks. Qaviar judges the response by computing recall against the stemmed
content words in the human-generated answer key. It counts the answer correct
if it exceeds agiven recall threshold. We determined that the answer
correctness predicted by Qaviar agreed with the human 93% to 95% of the time.
41 question-answering systems were ranked by both Qaviar and human assessors,
and these rankings correlated with a Kendall's Tau measure of 0.920, compared
to a correlation of 0.956 between human assessors on the same data.Comment: 6 pages, 3 figures, to appear in Proceedings of the Second
International Conference on Language Resources and Evaluation (LREC 2000
Magnetothermodynamics: Measuring equations of state in a relaxed magnetohydrodynamic plasma
We report the first measurements of equations of state of a fully relaxed
magnetohydrodynamic (MHD) laboratory plasma. Parcels of magnetized plasma,
called Taylor states, are formed in a coaxial magnetized plasma gun, and are
allowed to relax and drift into a closed flux conserving volume. Density, ion
temperature, and magnetic field are measured as a function of time as the
Taylor states compress and heat. The theoretically predicted MHD and double
adiabatic equations of state are compared to experimental measurements. We find
that the MHD equation of state is inconsistent with our data.Comment: 4 pages, 4 figure
17 ways to say yes:Toward nuanced tone of voice in AAC and speech technology
People with complex communication needs who use speech-generating devices have very little expressive control over their tone of voice. Despite its importance in human interaction, the issue of tone of voice remains all but absent from AAC research and development however. In this paper, we describe three interdisciplinary projects, past, present and future: The critical design collection Six Speaking Chairs has provoked deeper discussion and inspired a social model of tone of voice; the speculative concept Speech Hedge illustrates challenges and opportunities in designing more expressive user interfaces; the pilot project Tonetable could enable participatory research and seed a research network around tone of voice. We speculate that more radical interactions might expand frontiers of AAC and disrupt speech technology as a whole
Exploring women’s employment in tourism under state-socialism: Experiences of tourism work in socialist Romania
Recent academic debate into women’s experiences of tourism employment has emphasised the extremely heterogeneous nature of such work and the need for sensitivity to local political, economic, social and cultural contexts. This paper focuses on one such context
which has received little attention – state socialism – and we explore women’s experiences of tourism work in socialist Romania. Such work had characteristics in common with non- socialist contexts, but in other ways took a form which was distinctive to the socialist state. It was characterised by extensive training, good pay, and opportunities for promotion (at least
to middle management level). The socialist state also devised unique solutions to the problem of the seasonality of tourism work. However women also faced extensive surveillance by the state’s security services and faced harsh penalties for under-performance
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