Investigation of the Relationship of Earthquakes and Underground Waste Disposal in The El Dorado Area, Arkansas

From December, 1983 to September, 1989 twelve small earthquakes were recorded for the El Dorado, Arkansas area. Magnitudes of these earthquakes were well below damaging levels. Prior to this time no seismicity was reported in the area, suggesting that the earthquakes were not naturally occurring and may have been the result of human activity. El Dorado is located at the margin of a region of underground waste brine disposal and along a major fault zone. Elevated pore pressures resulting from brine disposal may have reduced the normal (locking) stresses across fault surfaces and triggered fault movement. Two injection wells (Great Lakes Chemical Corporation SWD# 7 and 13) in the El Dorado South field are in closest proximity to fault surfaces at the depth of injection. The two wells also lie at the center of the macroseismic area and show increases in injection rates prior to periods of seismicity. These relationships suggest that pressured fluid injection triggers earthquakes in the area. Future research to corroborate these results should include detailed seismological studies of the El Dorado South field and detailed studies of formation pressures, in situ stresses and geologic structure for all sites of pressured fluid injection and secondary oil recovery operations in the region

Relationships between temperament and live animal body composition traits in crossbred stocker steers

Last updated: 6/12/200

Exploiting the capacity of 1mm PMMA step-index polymer optical fibers

Three different techniques are discussed that are currently under investigation at Siemens Corporate Technology – Information and Communications in order to exploit the bandwidth capacity of 1 mm PMMA Step-Index Polymer Optical Fiber (SI-POF). By using Adaptive Multitone Modulation (AMTM) a record result of 540 Mb/s transmission over 100 m of SI-POF is achieved

Synaptic Cleft Segmentation in Non-Isotropic Volume Electron Microscopy of the Complete Drosophila Brain

Neural circuit reconstruction at single synapse resolution is increasingly recognized as crucially important to decipher the function of biological nervous systems. Volume electron microscopy in serial transmission or scanning mode has been demonstrated to provide the necessary resolution to segment or trace all neurites and to annotate all synaptic connections. Automatic annotation of synaptic connections has been done successfully in near isotropic electron microscopy of vertebrate model organisms. Results on non-isotropic data in insect models, however, are not yet on par with human annotation. We designed a new 3D-U-Net architecture to optimally represent isotropic fields of view in non-isotropic data. We used regression on a signed distance transform of manually annotated synaptic clefts of the CREMI challenge dataset to train this model and observed significant improvement over the state of the art. We developed open source software for optimized parallel prediction on very large volumetric datasets and applied our model to predict synaptic clefts in a 50 tera-voxels dataset of the complete Drosophila brain. Our model generalizes well to areas far away from where training data was available

Radiative forcing from modelled and observed stratospheric ozone changes due to the 11-year solar cycle

International audienceThree analyses of satellite observations and two sets of model studies are used to estimate changes in the stratospheric ozone distribution from solar minimum to solar maximum and are presented for three different latitudinal bands: Poleward of 30° north, between 30° north and 30° south and poleward of 30° south. In the model studies the solar cycle impact is limited to changes in UV fluxes. There is a general agreement between satellite observation and model studies, particular at middle and high northern latitudes. Ozone increases at solar maximum with peak values around 40 km. The profiles are used to calculate the radiative forcing (RF) from solar minimum to solar maximum. The ozone RF, calculated with two different radiative transfer schemes is found to be negligible (a magnitude of 0.01 Wm?2 or less), compared to the direct RF due to changes in solar irradiance, since contributions from the longwave and shortwave nearly cancel each other. The largest uncertainties in the estimates come from the lower stratosphere, where there is significant disagreement between the different ozone profiles

Dragging a polymer chain into a nanotube and subsequent release

We present a scaling theory and Monte Carlo (MC) simulation results for a flexible polymer chain slowly dragged by one end into a nanotube. We also describe the situation when the completely confined chain is released and gradually leaves the tube. MC simulations were performed for a self-avoiding lattice model with a biased chain growth algorithm, the pruned-enriched Rosenbluth method. The nanotube is a long channel opened at one end and its diameter $D$ is much smaller than the size of the polymer coil in solution. We analyze the following characteristics as functions of the chain end position $x$ inside the tube: the free energy of confinement, the average end-to-end distance, the average number of imprisoned monomers, and the average stretching of the confined part of the chain for various values of $D$ and for the number of monomers in the chain, $N$. We show that when the chain end is dragged by a certain critical distance $x^*$ into the tube, the polymer undergoes a first-order phase transition whereby the remaining free tail is abruptly sucked into the tube. This is accompanied by jumps in the average size, the number of imprisoned segments, and in the average stretching parameter. The critical distance scales as $x^*\sim ND^{1-1/\nu}$. The transition takes place when approximately 3/4 of the chain units are dragged into the tube. The theory presented is based on constructing the Landau free energy as a function of an order parameter that provides a complete description of equilibrium and metastable states. We argue that if the trapped chain is released with all monomers allowed to fluctuate, the reverse process in which the chain leaves the confinement occurs smoothly without any jumps. Finally, we apply the theory to estimate the lifetime of confined DNA in metastable states in nanotubes.Comment: 13pages, 14figure

Modeling the climate impact of Southern Hemisphere ozone depletion:the importance of the ozone dataset

The ozone hole is an important driver of recent Southern Hemisphere (SH) climate change, and capturing these changes is a goal of climate modeling. Most climate models are driven by off-line ozone data sets. Previous studies have shown that there is a substantial range in estimates of SH ozone depletion, but the implications of this range have not been examined systematically. We use a climate model to evaluate the difference between using the ozone forcing (Stratospheric Processes and their Role in Climate (SPARC)) used by many Intergovernmental Panel on Climate Change Fifth Assessment Report (Coupled Model Intercomparison Project) models and one at the upper end of the observed depletion estimates (Binary Database of Profiles (BDBP)). In the stratosphere, we find that austral spring/summer polar cap cooling, geopotential height decreases, and zonal wind increases in the BDBP simulations are all doubled compared to the SPARC simulations, while tropospheric responses are 20–100% larger. These results are important for studies attempting to diagnose the climate fingerprints of ozone depletion

Relationship Between Net Feed Intake, Performance Traits and Ultrasound Measures of Composition in Beef Steers

Last updated: 6/12/200