62 research outputs found
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Integration of pneumatic fracturing and in situ vitrification in the soil subsurface
Pacific Northwest Laboratory is evaluating ways to increase the applicability of the in situ vitrification (ISV) process at hazardous and radioactive waste sites. One innovation is the placement of a conductive material that will facilitate initiating the ISV process at a target depth. A series of laboratory tests performed at the New Jersey Institute of Technology (NJIT) assessed the feasibility of pneumatic fracturing (PF) in the highly permeable soils of the Hanford Site. The NJIT tests included an analysis of Hanford soils, a series of PF injection tests, and a parametric analysis to determine how soil properties affect the PF process. Results suggest that the PF process can be applied to Hanford soils and that dry medium (e.g., conductive material such as graphite flake) can be injected into the fracture. This paper describes the laboratory testing performed at NJIT, its results, and the application of those results to plans for a field demonstration at Hanford
Typical support and Sanov large deviations of correlated states
Discrete stationary classical processes as well as quantum lattice states are
asymptotically confined to their respective typical support, the exponential
growth rate of which is given by the (maximal ergodic) entropy. In the iid case
the distinguishability of typical supports can be asymptotically specified by
means of the relative entropy, according to Sanov's theorem. We give an
extension to the correlated case, referring to the newly introduced class of
HP-states.Comment: 29 pages, no figures, references adde
Carnitine Acetyltransferase Mitigates Metabolic Inertia and Muscle Fatigue during Exercise
SummaryAcylcarnitine metabolites have gained attention as biomarkers of nutrient stress, but their physiological relevance and metabolic purpose remain poorly understood. Short-chain carnitine conjugates, including acetylcarnitine, derive from their corresponding acyl-CoA precursors via the action of carnitine acetyltransferase (CrAT), a bidirectional mitochondrial matrix enzyme. We show here that contractile activity reverses acetylcarnitine flux in muscle, from net production and efflux at rest to net uptake and consumption during exercise. Disruption of this switch in mice with muscle-specific CrAT deficiency resulted in acetyl-CoA deficit, perturbed energy charge, and diminished exercise tolerance, whereas acetylcarnitine supplementation produced opposite outcomes in a CrAT-dependent manner. Likewise, in exercise-trained compared to untrained humans, post-exercise phosphocreatine recovery rates were positively associated with CrAT activity and coincided with dramatic shifts in muscle acetylcarnitine dynamics. These findings show acetylcarnitine serves as a critical acetyl buffer for working muscles and provide insight into potential therapeutic strategies for combatting exercise intolerance
Complex Langevin: Etiology and Diagnostics of its Main Problem
The complex Langevin method is a leading candidate for solving the so-called
sign problem occurring in various physical situations. Its most vexing problem
is that in some cases it produces `convergence to the wrong limit'. In the
first part of the paper we go through the formal justification of the method,
identify points at which it may fail and identify a necessary and sufficient
criterion for correctness. This criterion would, however, require checking
infinitely many identities, and therefore is somewhat academic. We propose
instead a truncation to the check of a few identities; this still gives a
necessary criterion, but a priori it is not clear whether it remains
sufficient. In the second part we carry out a detailed study of two toy models:
first we identify the reasons why in some cases the method fails, second we
test the efficiency of the truncated criterion and find that it works perfectly
at least in the toy models studied.Comment: 39 pages, 15 figures; typos corrected and reference adde
First Measurement of Z/gamma* Production in Compton Scattering of Quasi-real Photons
We report the first observation of Z/gamma* production in Compton scattering
of quasi-real photons. This is a subprocess of the reaction e+e- to
e+e-Z/gamma*, where one of the final state electrons is undetected.
Approximately 55 pb-1 of data collected in the year 1997 at an e+e-
centre-of-mass energy of 183 GeV with the OPAL detector at LEP have been
analysed. The Z/gamma* from Compton scattering has been detected in the
hadronic decay channel. Within well defined kinematic bounds, we measure the
product of cross-section and Z/gamma* branching ratio to hadrons to be
(0.9+-0.3+-0.1) pb for events with a hadronic mass larger than 60 GeV,
dominated by (e)eZ production. In the hadronic mass region between 5 GeV and 60
GeV, dominated by (e)egamma* production, this product is found to be
(4.1+-1.6+-0.6) pb. Our results agree with the predictions of two Monte Carlo
event generators, grc4f and PYTHIA.Comment: 18 pages, LaTeX, 5 eps figures included, submitted to Physics Letters
The use of immunological techniques and scanning confocal laser microscopy for the characterization of Agrobacterium tumefaciens and Pseudomonas fluorescens, atrazine-utilizing biofilms.
Thermal cycling-induced changes in excess dark current in very long-wavelength HgCdTe photodiodes at low temperature
Grenzen und Möglichkeiten bei der Analytik mit Dansylchlorid, I. Reaktion von aromatischen Sulfonylchloriden mit aliphatischen tertiären Aminen: Der Hinsberg-Test unter mikroanalytischen Gesichtspunkten
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