11,671 research outputs found
A methodology for the environmental assessment of advanced coal extraction systems
Procedures developed to identify and assess potential environment impacts of advanced mining technology as it moves from a generic concept to a more systems definition are described. Two levels of assessment are defined in terms of the design stage of the technology being evaluated. The first level of analysis is appropriate to a conceptual design. At this level it is assumed that each mining process has known and potential environmental impacts that are generic to each mining activity. By using this assumption, potential environmental impacts can be identified for new mining systems. When two or more systems have been assessed, they can be evaluated comparing potential environmental impacts. At the preliminary stage of design, a systems performance can be assessed again with more precision. At this level of systems definition, potential environmental impacts can be analyzed and their significane determined in a manner to facilitate comparisons between systems. At each level of analysis, suggestions calculated to help the designer mitigate potentially harmful impacts are provided
The enviornmental assessment of a contemporary coal mining system
A contemporary underground coal mine in eastern Kentucky was assessed in order to determine potential off-site and on-site environmental impacts associated with the mining system in the given environmental setting. A 4 section, continuous room and pillor mine plan was developed for an appropriate site in eastern Kentucky. Potential environmental impacts were identified, and mitigation costs determined. The major potential environmental impacts were determined to be: acid water drainage from the mine and refuse site, uneven subsidence of the surface as a result of mining activity, and alteration of ground water aquifers in the subsidence zone. In the specific case examined, the costs of environmental impact mitigation to levels prescribed by regulations would not exceed $1/ton of coal mined, and post mining land values would not be affected
High-throughput in-situ characterization and modelling of precipitation kinetics in compositionally graded alloys
The development of new engineering alloy chemistries is a time consuming and
iterative process. A necessary step is characterization of the
nano/microstructure to provide a link between the processing and properties of
each alloy chemistry considered. One approach to accelerate the identification
of optimal chemistries is to use samples containing a gradient in composition,
ie. combinatorial samples, and to investigate many different chemistries at the
same time. However, for engineering alloys, the final properties depend not
only on chemistry but also on the path of microstructure development which
necessitates characterization of microstructure evolution for each chemistry.
In this contribution we demonstrate an approach that allows for the in-situ,
nanoscale characterization of the precipitate structures in alloys, as a
function of aging time, in combinatorial samples containing a composition
gradient. The approach uses small angle x-ray scattering (SAXS) at a
synchrotron beamline. The Cu-Co system is used for the proof-of-concept and the
combinatorial samples prepared contain a gradient in Co from 0% to 2%. These
samples are aged at temperatures between 450{\textdegree}C and
550{\textdegree}C and the precipitate structures (precipitate size, volume
fraction and number density) all along the composition gradient are
simultaneously monitored as a function of time. This large dataset is used to
test the applicability and robustness of a conventional class model for
precipitation that considers concurrent nucleation, growth and coarsening and
the ability of the model to describe such a large dataset.Comment: Published in Acta Materiali
RSRM-11 (36OW011) ballistics mass properties (STS-35)
The propulsion performance and reconstructed mass properties data from Thiolol's RSRM-11 motors which were assigned to the STS-35 launch are contained. The Thiokol manufacturing designations for the motors were 360W011A/360W011B, which are referred to as RSRM-11A and RSRM-B, respectively. The launch of STS-35 occurred on 2 December 1990 at the Eastern Test Range (ETR). The data contained herein was input to the STS-35 Flight Evaluation Report. The SRM propellant, TP-H1148, is a composite type solid propellants, formulated of polybutediene acrylic acid, acryonitrile terpolymer binder, epoxy curing agent, ammonium perchlorate oxidizer, and aluminum powder fuel. A small amount of burning rate catalyst (iron oxide) was added to achieve the desired propellant burn rate. The propellant evaluation and raw material information for the RSRM-11 are included. The ballistic performance presented was based on the Operational Flight Instrumentation (OFI) 12.5 sample per second pressure data for the steady state and tail off portion of the pressure trace. Recent studies have shown that the transducers are affected by the measuring system at KSC and temperature gradients created by the igniter heaters. Therefore, an adjustment to the data from each transducer is made to make the initial reading match the atmospheric pressure at the time of launch
Morphine activates neuroinflammation in a manner parallel to endotoxin
Opioids create a neuroinflammatory response within the CNS, compromising opioid-induced analgesia and contributing to various unwanted actions. How this occurs is unknown but has been assumed to be via classic opioid receptors. Herein, we provide direct evidence that morphine creates neuroinflammation via the activation of an innate immune receptor and not via classic opioid receptors. We demonstrate that morphine binds to an accessory protein of Toll-like receptor 4 (TLR4), myeloid differentiation protein 2 (MD-2), thereby inducing TLR4 oligomerization and triggering proinflammation. Small-molecule inhibitors, RNA interference, and genetic knockout validate the TLR4/MD-2 complex as a feasible target for beneficially modifying morphine actions. Disrupting TLR4/MD-2 protein–protein association potentiated morphine analgesia in vivo and abolished morphine-induced proinflammation in vitro, the latter demonstrating that morphine-induced proinflammation only depends on TLR4, despite the presence of opioid receptors. These results provide an exciting, nonconventional avenue to improving the clinical efficacy of opioids.Xiaohui Wang, Lisa C. Loram, Khara Ramos, Armando J. de Jesus, Jacob Thomas, Kui Cheng, Anireddy Reddy, Andrew A. Somogyi, Mark R. Hutchinson, Linda R. Watkins and Hang Yi
Disruption of reflecting Bose-Einstein condensates due to inter-atomic interactions and quantum noise
We perform fully three-dimensional simulations, using the truncated Wigner
method, to investigate the reflection of Bose-Einstein condensates from abrupt
potential barriers. We show that the inter-atomic interactions can disrupt the
internal structure of a cigar-shaped cloud with a high atom density at low
approach velocities, damping the center-of-mass motion and generating vortices.
Furthermore, by incorporating quantum noise we show that scattering halos form
at high approach velocities, causing an associated condensate depletion. We
compare our results to recent experimental observations.Comment: 5 figure
Electron Temperature of Ultracold Plasmas
We study the evolution of ultracold plasmas by measuring the electron
temperature. Shortly after plasma formation, competition between heating and
cooling mechanisms drives the electron temperature to a value within a narrow
range regardless of the initial energy imparted to the electrons. In agreement
with theory predictions, plasmas exhibit values of the Coulomb coupling
parameter less than 1.Comment: 4 pages, plus four figure
Observation of magnetocoriolis waves in a liquid metal Taylor-Couette experiment
The first observation of fast and slow magnetocoriolis (MC) waves in a
laboratory experiment is reported. Rotating nonaxisymmetric modes arising from
a magnetized turbulent Taylor-Couette flow of liquid metal are identified as
the fast and slow MC waves by the dependence of the rotation frequency on the
applied field strength. The observed slow MC wave is damped but the observation
provides a means for predicting the onset of the Magnetorotational Instability
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