16,799 research outputs found
Reconsideration of Interlocutory Orders: A Critical Reassessment of Calloway v. Ford Motor Co. and Whether One Judge May Overrule Another
Stability of Impurities with Coulomb Potential in Graphene with Homogeneous Magnetic Field
Given a 2-dimensional no-pair Weyl operator with a point nucleus of charge Z,
we show that a homogeneous magnetic field does not lower the critical charge
beyond which it collapses.Comment: J. Math. Phys. (in press
An Experimental and Modeling Study on the Response to Varying Pore Pressure and Reservoir Fluids in the Morrow A Sandstone
In mature oil fields undergoing enhanced oil recovery methods, such as CO2 injection, monitoring the reservoir changes becomes important. To understand how reservoir changes influence compressional wave (P) and shear wave (S) velocities, we conducted laboratory core experiments on five core samples taken from the Morrow A sandstone at Postle Field, Oklahoma. The laboratory experiments measured P- and S-wave velocities as a function of confining pressure, pore pressure, and fluid type (which included CO2 in the gas and supercritical phase). P-wave velocity shows a response that is sensitive to both pore pressure and fluid saturation. However, S-wave velocity is primarily sensitive to changes in pore pressure. We use the fluid and pore pressure response measured from the core samples to modify velocity well logs through a log facies model correlation. The modified well logs simulate the brine- and CO2-saturated cases at minimum and maximum reservoir pressure and are inputs for full waveform seismic modeling. Modeling shows how P- and S-waves have a different time-lapse amplitude response with offset. The results from the laboratory experiments and modeling show the advantages of combining P- and S-wave attributes in recognizing the mechanism responsible for time-lapse changes due to CO2 injection
Using Watershed Pour-Point Elevations to Evaluate the Base of Fresh Groundwater in the Cumberland Plateau of Eastern Kentucky
Horizontal drilling with hydraulic fracturing at shallow depths (less than 2,200 ft) in the Devonian Berea Sandstone oil and gas play, along with the potential for high-volume hydraulic fracturing in the nascent Cambrian Rogersville Shale gas play, have generated a renewed interest in protecting groundwater quality in eastern Kentucky. A critical component of protection is an accurate understanding of the distribution of fresh water in the subsurface. The “Fresh-Saline Water Interface Map of Kentucky” by H.T. Hopkins, published by the U.S. Geological Survey and Kentucky Geological Survey in 1966, has been a critical reference for assessing the maximum depth of fresh groundwater and is an important guidance document for well operators and regulatory agencies. To create the map, Hopkins assumed that total depth of domestic water wells equaled the base of fresh groundwater (total dissolved solids less than 1,000 ppm). Most domestic wells fail to penetrate the deepest fresh groundwater, however, and consequently, Hopkins’s map likely underestimates the depth of the fresh-saline water interface.
Our study also used total depths of wells to map the base of fresh groundwater, but increased the data density by adding data from domestic water wells drilled after 1966. In the 14-county study area, the number of wells increased from 50 used by Hopkins to 4,824 in this study. Total well depths were contour mapped using Petra software. Despite the increased data density, the inclusion of a greater number of shallow wells produced contour patterns that impeded resolution of deep fresh groundwater distribution (i.e., noise). To limit the influence of shallow wells, we eliminated wells with total depths above the elevations of watershed pour points in each watershed defined by 14- and 11-digit hydrologic unit codes. This excluded wells that did not penetrate the deepest fresh groundwater in low-order watersheds. We then created maps based on all wells with total depths below the elevations of their respective pour points in 14- and 11-digit hydrologic units (n = 3,203 and 854, respectively), as well as maps based on the single deepest well in the 14- and 11-digit hydrologic units (n = 1,420 and 74, respectively). The pour-point method improved the resolution of deep fresh groundwater distribution, and the map using the single deepest well depth in each 11-digit hydrologic unit provided the clearest illustration of deep fresh groundwater distribution.
Throughout most of the study area, the estimated depth of fresh groundwater derived from the 11-digit hydrologic unit deepest-well map is, on average, 147 ft deeper than the interface shown on the Hopkins map; in eastern Lawrence County, the difference exceeds 500 ft. Even though our study resulted in an improved estimate of maximum fresh groundwater depth, uncertainties remain in the data and methods. To reflect this uncertainty, the term “deepest observed fresh water” should be used as an alternative to “fresh-saline water interface.
Pro and anti-inflammatory cytokine levels (TNF- , IL-1 , IL-6 andIL-10) in rat model of neuroma
Traumatic neuroma is neuronal tissue proliferation developed in a nerve injury site, often associatedwith increased sensitivity and spontaneous or evoked neuropathic pain. The mechanisms leading to the disorganized nerve proliferation are not completely understood, though inflammation in the injured nerve vicinity most likely has a role in the process. Inflammatory cytokines are also known to be involvedin the maintenance and development of post-traumatic and neuropathic pain. The goal of this study wasto quantify and compare pro and anti-inflammatory cytokines (TNF- , IL-1 , IL-6 and IL-10) levels innerves that formed neuromas and nerves that did not, following sciatic nerve transection.
A total of 30 rats were used in this study. Twenty rats underwent sciatic nerve transection and 10underwent sham surgery. Six weeks post-surgery nerve sections were collected and histologically eval-uated for neuroma formation. The samples were then classified as neuroma, non-neuroma and shamgroups. TNF- , IL-1 , IL-6 and IL-10 levels were measured in the nerves employing ELISA. TNF- levels were significantly higher in both neuroma and non-neuroma-forming injured nerves compared to thesham group. IL-1 and IL-6 levels were significantly higher in the neuroma-forming nerves compared tothe sham group. IL-10 levels were significantly higher in the non-neuroma group compared to the shamgroup. In conclusion IL-6, and IL-1 may have a role in the formation of traumatic neuroma while IL-10may inhibit neuroma formation
Efficacy of Blended E-Learning Tools: A Case Study
In the past 5 years, interest in distance learning has increased, and use of e-learning tools has become more widely accepted by academics. With such a wide variety of e-learning tools to choose from, what really works? How might we augment our traditional teaching tools with a blend of the new e-learning tools to better reach audiences? In this article, we discuss the efficacy of a set of blended e-learning tools — blogs, podcasts, enhanced podcasts, Internet telephony and instant messaging, news aggregators, collaborative project management software, and Web/video conferencing — used to teach Ohio State University (OSU) professionals about knowledge economy programming. We share implications of survey findings from this population and provide recommendations for others interested in initiating or improving their distance learning efforts with these tools
Determining the influence and effects of manufacturing variables on sulfur dioxide cells
A survey of the Li/SO2 manufacturing community was conducted to determine where variability exists in processing. The upper and lower limits of these processing variables might, by themselves or by interacting with other variables, influence safety, performance, and reliability. A number of important variables were identified and a comprehensive design experiment is being proposed to make the proper determinations
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