4,729 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
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
Use of Ethyl (E,Z)-2,4-decadienoate in Codling Moth Management: Kairomone Species Specificity
Ethyl (E,Z)-2,4-decadienoate (pear ester) is a kairomonal attractant for both male and female codling moth, Cydia pomonella (L.), in apple, pear and walnut. Studies were conducted in the western Untied States to evaluate the potential attractiveness of this kairomone for eight lepidopteran pests of these three crops, as well as, in cherry, peach/nectarine, apricot, plum, almond, pistachio, grape, kiwi, and citrus. The pear ester was loaded (10.0 mg) into gray halobutyl septa and insects were monitored with diamond- or delta-shaped sticky traps. Lures were not attractive to peach twig borer, Anarsia lineatella (Zeller); oriental fruit moth, Cydia molesta (Busck); omnivorous leafroller, Platynota stultana Walshingham; navel orangeworm, Amyelois transitella (Walker); apple fruitworm, Lacanobia subjuncta (Grote & Robinson); pandemis leafroller, Pandemis pyrusana (Kearfott); obliquebanded leafroller, Choristoneura rosaceana (Harris); and western tentiform leafminer, Phyllonorycter mespiella (Hüebner). Additional studies with C. molesta populations attacking apple and pear would be useful
Use of Ethyl and Propyl (E,Z)-2,4-decadienoates in Codling Moth Management: Improved Monitoring in Bartlett Pear with High Dose Lures
The propyl and ethyl esters of (E,Z)-2,4-decadienoic acid were evaluated in gray halobutyl septa as kairomone lures for both sexes of codling moth, Cydia pomonella (L.). All studies were conducted in 'Bartlett' pear orchards with moderate to high codling moth adult population densities and treated with sex pheromone dispensers for mating disruption. Variable results were obtained with kairomone loading experiments. Increasing the lure loading to 40.0 mg of either the ethyl or propyl ester significantly increased male and total moth catch in separate experiments. However, in other tests with the ethyl ester no difference was found in total moth catch in traps baited with 0.1, 1.0, 3.0 or 10.0 mg versus 40.0 mg lures. The 40.0 mg ethyl and propyl ester lures were both more effective than a 3.0 mg ethyl ester lure and comparable to a sex pheromone lure in detecting the beginning of codling moth flight in the spring generation. No difference was found in moth catch between 40.0 mg propyl and ethyl ester lures. Significantly more females were caught in traps baited with 1.0 – 10.0 mg than with 1.0 – 100.0 μg lures loaded with the ethyl ester. In general, kairomone lures caught significantly fewer moths than sex pheromone lures
Use of Ethyl (E,Z)-2,4-decadienoate in Codling Moth Management: Stimulation of Oviposition
The effect of the pear volatile, ethyl (E,Z)-2,4-decadienoate (Et-E,Z-DD), on oviposition by codling moth, Cydia pomonella (L.), was evaluated in a series of choice and nochoice laboratory experiments and in subsequent field tests conducted in apple and walnut. Gray halobutyl elastomer septa loaded with 1.0 and 100.0 μg Et-E,Z-DD significantly increased the numbers of eggs laid by a laboratory population in 96 h no-choice assays by 2-fold. In addition, the number of eggs laid near the Et-E,Z-DD versus a solvent blank dispenser was significantly higher in choice bioassays across a similar range of septa loadings. Oviposition rates by a field-collected post-diapause strain of codling moth were significantly increased by the addition of a 1.0-μg septa versus a solvent blank dispenser in a no-choice bioassay. Field trials were conducted in apple and walnut to develop an artificial egg trap baited with Et-E,Z-DD to monitor codling moth oviposition. Septa loaded with 0.1 to 10.0 mg did not significantly increase oviposition versus solvent blank dispensers on a Mylar plastic collar trap or on the adjacent leaves and fruit in apple. Significantly more eggs were laid on the fruit and foliage than on the plastic collar. No eggs were deposited on non-bearing apple shoots baited with 0.1 – 40.0 mg Et-E,Z-DD septa. Similarly, no eggs were deposited on cylindrical wax paper-covered plastic traps baited with 10.0 μg to 1.0 mg Et-E,Z-DD septa in walnut orchards. The potential of Et-E,Z-DD to monitor codling moth’s oviposition in the field, stimulate oviposition by field-collected strains under laboratory conditions, and to improve pest control by disrupting host location are discussed
Magnetothermodynamics: An Experimental Study Of The Equations Of State Applicable To A Magnetized Plasma
Measuring the equations of state of a compressed magnetized plasma is important for both advancing fusion experiments and understanding natural systems such as stellar winds. In this paper, we present results from our experiments on the thermodynamics of compressed magnetized plasmas; we call these studies “magnetothermodynamics.” In these experiments, we generate parcels of relaxed, magnetized plasma at one end of the linear Swarthmore Spheromak eXperimental device and observe their compression in a closed conducting boundary installed at the other end. Plasma parameters are measured during compression. Instances of ion heating during compression are identified by constructing a pressure-volume diagram using the measured density, temperature, and volume of the magnetized plasma. An axial scan of the ion temperature at upstream locations suggests that the increase in ion temperature arises due to the compression of the magnetized plasma in the conducting boundary. The theoretically predicted magnetohydrodynamic (MHD) and double adiabatic equations of state are compared with experimental measurements to estimate the adiabatic nature of the compressed plasma. The equilibrium of our magnetized plasmas is well-described by magnetohydrodynamics; however, we find that the MHD equation of state is not supported by our data. Our results are more consistent with the parallel Chew-Goldberger-Low equation of state, suggesting that there is significant anisotropy in the ion distribution function
Measuring The Equations Of State In A Relaxed Magnetohydrodynamic Plasma
We report measurements of the 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
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