330 research outputs found
The H\"older Inequality for KMS States
We prove a H\"older inequality for KMS States, which generalises a well-known
trace-inequality. Our results are based on the theory of non-commutative
-spaces.Comment: 10 page
Pair Production from 10 GeV to 10 ZeV
At very high energies, pair production () exhibits many
interesting features. The momentum transfer from the target is very small, so
the reaction probes the macroscopic properties of the target, rather than
individual nuclei. Interference between interactions with different atoms
reduces the pair production cross section considerably below the Bethe-Heitler
values. At very high energies, photonuclear interactions may outnumber pair
production.
In contrast, in crystals, the interaction amplitudes may add coherently,
greatly increasing the cross sections. Pair production in matter-free magnetic
fields is also possible. The highest energy pair production occurs at high
energy particle colliders. This article will compare pair production in these
very different regimes.Comment: 37 pages with 9 figures. Invited Review for "Radiation Physics and
Chemistry" Version for publication, incorporating comments by the referee,
and by Gerhard Baur and Roman Le
Low-Silica and High-Calcium Stone in the Newman Limestone (Mississippian) on Pine Mountain, Harlan County, Southeastern Kentucky
The coal industry of Kentucky is an important market for limestone. Coal producers use limestone as rock dust for explosion abatement in underground coal mines and as a neutralizing agent in surface-mine reclamation and acid-drainage control. Crushed stone is also used for constructing and maintaining haulage roads.
In the Eastern Kentucky Coal Field, the coal-bearing rocks of Pennsylvanian age generally do not contain limestones that are thick enough to quarry or mine economically. But movement on the Pine Mountain overthrust fault has brought the Newman Limestone (Mississippian) to the surface along Pine Mountain in the southeastern part of the coal field.
The Newman on Pine Mountain in Harlan County was sampled at 1-foot intervals to determine its chemical quality and potential for industrial use, particular as low-silica rock dust. The sampled section contains two zones of low-silica stone, 64 and 25 feet thick, averaging 0.82 and 1.01 percent silica (SiO2), respectively. Intervals of high-calcium limestone are present in the low-silica zones. These deposits are potentially suitable for use as rock dust in underground coal mines and as neutralizing agents in surface-mine reclamation and acid-drainage control.
The intervals of chemically pure stone in Harlan County may be sufficiently thick to produce by selective quarrying or underground mining. Exploitation of the Newman deposits, however, will be complicated by the steep southeastward to southward dip (13 to 42°) of the beds, displacement along small faults within the limestone, and fracturing
Coal Ash By-Product from Shanxi Province, China, for the Production of Portland–Calcium Sulfoaluminate
Twenty bulk samples were collected from ponded coal combustion ash in Shanxi Province, China, as part of an investigation of their beneficiation potential. The samples were shipped to the University of Kentucky, where they were chemically analyzed. The samples were highly consistent in chemistry, falling within the ASTM C-618 class F compositional range. The particle size of the ponded ash was relatively coarse, with only ,7% by weight on average, falling below 200 mesh (75 mm) particle size. The bulk of the material (.80%) was within 50 by 200 mesh (equivalent to 300 by 75 mm). X-ray diffraction investigation combined with microscopy indicated that the agglomeration was probably due to the presence of small amounts (i.e., ,3.5%) of gypsum. The utilization potential of the ash was assessed in light of its characteristics and location. The presence of sulfate and relatively high alumina concentration, which averaged ,37%, suggested that it may serve as an important ingredient in the fabrication of a Portland–calcium sulfoaluminate (CSA) hybrid cement. Portland-CSA hybrid clinkers were successfully produced from this ponded ash when mixed with hydrated lime, gypsum, fluorite, and bauxite. The raw mixture was fired at 1250uC for 60 minutes twice (sample D) and consisted of approximately 40% alite (C3S), 21% belite (C2S), 3% ferrite (brownmillerite or C4AF), 32% CSA (ye’elimite, Klein’s compound, or C4A3SO3), and no free lime by weight
Low-Silica and High-Calcium Stone in the Newman Limestone (Mississippian) on Pine Mountain, Letcher County, Southeastern Kentucky
The coal industry of Kentucky is an important market for limestone. Coal producers use limestone as rock dust for explosion abatement in underground coal mines and as a neutralizing agent in surface-mine reclamation and acid-drainage control. Haulage-road construction and maintenance require crushed stone.
Coal-bearing rocks of Pennsylvanian age in the Eastern Kentucky Coal Field generally do not contain limestones that are sufficiently thick to quarry or mine economically, but in the southeastern part of the coal field, fault movement has brought the Newman Limestone to the surface along Pine Mountain. The Newman was sampled at three sites in Letcher County to determine its chemical quality and potential for industrial use, particularly as a source of low-silica rock dust. Analysis of the foot-by-foot samples shows that the Newman contains several zones of low-silica stone, 10 to 39 feet thick. A few intervals of high-calcium limestone, 12 to 24 feet thick, coincide with or occur in the low-silica zones. The deposits of low-silica and high-calcium stone are thickest in the southwestern part of Letcher County and commonly thin northeastward.
The thicker deposits of chemically pure limestone and dolomite may be an economically exploitable source of rock dust for underground coal mines, and a source of stone for surface-mine reclamation and acid-drainage control. Production from deposits in the Newman, however, will be complicated by the steep southeastward to southward dip (20 to 42°) of the beds, possible displacement along small faults, and fracturing of the limestone
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Demonstration of Technology for the Production of High Value Materials from the Ultra-Fine (PM 2.5) Fraction of Coal Combustion Ash
Three types of chemically and functionally different thermoplastic polymers have been chosen for evaluation with the fly ash derived filler: high density polyethylene (HDPE), thermoplastic elastomer (TPE) and polyethylene terephthalate (PET). The selections were based on volumes consumed in commercial and recycled products. The reference filler selected for comparison was 3 {micro}m calcium carbonate, a material which is commonly used with all three types of polymers. A procedure to prepare filled polymers has been developed and the polymer/filler blends have been prepared. Selected samples of filled polymers were subjected to SEM analysis to verify that the fly ash derived filler and the calcium carbonate were well dispersed. Material taken from a utility ash pond was classified using a novel combination of hydraulic and lamellar classifiers to produce an ultra-fine ash product. This product was dried and used in a series of tests to determine its potential as a filler in plastics. The general properties of the ultra-fine ash from several runs are as follows: D{sub 50}: 3-5 {micro}m; Specific gravity: {approx}2.41; Loss on ignition: 2-3%; Carbon content: 1-2%; Color: dark grey on content: 1-2%; and Morphology: spherical. The addition of fillers increased the modulus of the HDPE composite, but decreased both the offset yield stress and offset yield strain, showing that the fillers essentially made the composite stiffer but the transition to plastic deformation occurred earlier in filled HDPE as stress was applied. Similar results were obtained with TPE, however, the decrease in either stress or strain at offset yield were not as significant. Dynamic mechanical analyses (DMA) were also completed and showed that although there were some alterations in the properties of the HDPE and TPE, with the addition of CaCO{sub 3} and fly ash, the alterations are small, and more importantly, transition temperatures are not altered. A utility patent on the design of the hydraulic classifier, described extensively during our last reporting period, was written and filled with the U. S. Patent and Trademark Office during the period
Altered expression of genes controlling metabolism characterizes the tissue response to immune injury in lupus.
To compare lupus pathogenesis in disparate tissues, we analyzed gene expression profiles of human discoid lupus erythematosus (DLE) and lupus nephritis (LN). We found common increases in myeloid cell-defining gene sets and decreases in genes controlling glucose and lipid metabolism in lupus-affected skin and kidney. Regression models in DLE indicated increased glycolysis was correlated with keratinocyte, endothelial, and inflammatory cell transcripts, and decreased tricarboxylic (TCA) cycle genes were correlated with the keratinocyte signature. In LN, regression models demonstrated decreased glycolysis and TCA cycle genes were correlated with increased endothelial or decreased kidney cell transcripts, respectively. Less severe glomerular LN exhibited similar alterations in metabolism and tissue cell transcripts before monocyte/myeloid cell infiltration in some patients. Additionally, changes to mitochondrial and peroxisomal transcripts were associated with specific cells rather than global signal changes. Examination of murine LN gene expression demonstrated metabolic changes were not driven by acute exposure to type I interferon and could be restored after immunosuppression. Finally, expression of HAVCR1, a tubule damage marker, was negatively correlated with the TCA cycle signature in LN models. These results indicate that altered metabolic dysfunction is a common, reversible change in lupus-affected tissues and appears to reflect damage downstream of immunologic processes
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