7,246 research outputs found
Quantum Geometry Phenomenology: Angle and Semiclassical States
The phenomenology for the deep spatial geometry of loop quantum gravity is
discussed. In the context of a simple model of an atom of space, it is shown
how purely combinatorial structures can affect observations. The angle operator
is used to develop a model of angular corrections to local, continuum
flat-space 3-geometries. The physical effects involve neither breaking of local
Lorentz invariance nor Planck scale suppression, but rather reply on only the
combinatorics of SU(2) recouping theory. Bhabha scattering is discussed as an
example of how the effects might be observationally accessible.Comment: 5 pages, slightly extended version of the contribution to the
Loops'11 conference proceeding
Spin-triplet paired phases inside ferromagnet induced by Hund's rule coupling and electronic correlations: Application to
We discuss a mechanism of real-space spin-triplet pairing, alternative to
that due to quantum paramagnon excitations, and demonstrate its applicability
to . Both the Hund's rule ferromagnetic exchange and
inter-electronic correlations contribute to the same extent to the equal-spin
pairing, particularly in the regime in which the weak-coupling solution does
not provide any. The theoretical results, obtained within the
orbitally-degenerate Anderson lattice model, match excellently the observed
phase diagram for with the coexistent ferromagnetic (FM1) and
superconducting (-type) phase. Additionally, weak - and -type
paired phases appear in very narrow regions near the metamaganetic (FM2
FM1) and FM1 paramagnetic first-order
phase-transition borders, respectively. The values of magnetic moments in the
FM2 and FM1 states are also reproduced correctly in a semiquantitative manner.
The Hund's metal regime is also singled out as appearing near FM1-FM2 boundary
The Electrostatic Ion Beam Trap : a mass spectrometer of infinite mass range
We study the ions dynamics inside an Electrostatic Ion Beam Trap (EIBT) and
show that the stability of the trapping is ruled by a Hill's equation. This
unexpectedly demonstrates that an EIBT, in the reference frame of the ions
works very similar to a quadrupole trap. The parallelism between these two
kinds of traps is illustrated by comparing experimental and theoretical
stability diagrams of the EIBT. The main difference with quadrupole traps is
that the stability depends only on the ratio of the acceleration and trapping
electrostatic potentials, not on the mass nor the charge of the ions. All kinds
of ions can be trapped simultaneously and since parametric resonances are
proportional to the square root of the charge/mass ratio the EIBT can be used
as a mass spectrometer of infinite mass range
Analysis of standing vertical jumps using a force platform
A force platform analysis of vertical jumping provides an engaging demonstration of the kinematics and dynamics of one-dimensional motion. The height of the jump may be calculated (1) from the flight time of the jump, (2) by applying the impulse–momentum theorem to the force–time curve, and (3) by applying the work–energy theorem to the force-displacement curve
Moderate intensity cycling following eccentric contractions does not attenuate indirect markers of muscle damage.
Unaccustomed eccentric muscle contraction causes prolonged changes to indirect markers of muscle damage (Clarkson & Hubal, 2002). It has been proposed that active recovery therapy (ART) consisting of non-eccentric based movements may aid in the recovery process uts of moderate intensity cycling in the followin(Sayers et al., 2000). The purpose of this investigation was to compare the effect of ART on changes in one repetition maximum (1RM), dynamic muscle function, swelling, delayed onset muscle soreness (DOMS), and changes in MRI T2 relaxation times post exercise induced muscle damage (EIMD). Ten previously trained participants (at least 1 lower body resistance training session a week) were recruited from within the university community and divided in two groups: a cycling ART group (CG, n = 5) who performed three bouts of moderate intensity cycling in the four days following the EIMD protocol and a non-cycling group (NCG, n= 5) who performed no cycling in the four days following the EIMD protocol. There were no statistical differences between the two treatment groups for height, weight or age (P \u3c 0.05). The EIMD protocol reduced 1RM, muscle function, elicited DOMS and increased swelling and T2 relaxation times in both CG and NCG (P \u3c0.05). In the 96 h period post the EIMD protocol no differences were observed between CG and NCG for the magnitude of change or rate of recovery. Three bouts of cycling ART performed at 24 h intervals after an EIMD did not improve indirect markers of muscle damage
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State Lands Energy Resource Optimization Project - 1992 Annual Progress Report
Project SLERO, for which The University of Texas at Austin Bureau of Economic Geology is the lead contractor and coordinating institution, is a five-university consortium study of hydrocarbon resources on Texas State Lands. The five universities are The University of Texas at Austin, Texas A&M University, the University of Houston, Texas Tech University, and Lamar University, and the entire program is aided by the cooperation of the Texas General Land Office. This is a four-year project funded at the level of 8 million of which was granted by the Office of the Governor of Texas and $8 million of which is matched by participating academic institutions.
Project personnel include geologists, petroleum engineers, geophysicists, and chemists. The interdisciplinary nature of this project is directed toward a more thorough understanding of the geologic controls on production and the development of appropriate recovery technologies to address the specific needs of State Lands reservoirs. Transfer of these technologies to industry, in particular to independent operators, is expected to result in increased efficiency of hydrocarbon recovery from State Lands and increased revenue to the Texas Public School Fund. The project is divided into three parts: (1) play analysis and resource assessment, (2) reservoir characterization, and (3) development of advanced extraction technology.
The play analysis and resource assessment part of this research program involves dividing the oil and gas fields on Texas State Lands into geologically based families, such that fields with similar depositional histories, trapping styles, production efficiencies, and extraction difficulties are grouped into "plays." Play analysis provides the framework for making a quantitative assessment of the remaining resources on State Lands. Importantly, even maturely developed oil reservoirs may still contain substantial volumes of both "mobile" oil (oil that is movable at reservoir conditions and that can be conventionally recovered) and "residual" oil (oil that requires expensive and technically complex reservoir stimulation). The relative amounts of these resource types vary among the geologically based plays. Quantifying the amounts of these two types of oil on State Lands, as well as quantifying the remaining natural gas resource, is critical both for designing field development programs and for optimizing the recovery economics of Texas hydrocarbon resources and is the focus of the resource assessment task.Bureau of Economic Geolog
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State Lands Energy Resource Optimization Project - Final Report
Project SLERO, for which The University of Texas at Austin Bureau of Economic Geology was the lead contractor and coordinating institution, was a five-university consortium study of hydrocarbon resources on Texas State Lands. The five universities are The University of Texas at Austin, Texas A&M University, the University of Houston, Texas Tech University, and Lamar University, and the entire program was aided by the cooperation of the Texas General Land Office. This 4-year project was funded through the Office of the Governor of Texas.
Project personnel included geologists, petroleum engineers, geophysicists, and chemists. The interdisciplinary nature of this project was directed toward a more thorough understanding of the geologic controls on production and the development of appropriate recovery technologies to address the specific needs of State Lands reservoirs. Transfer of these technologies to industry, in particular to independent operators, is expected to result in increased efficiency of hydrocarbon recovery from State Lands and increased revenue to the Texas Public School Fund. The project was divided into three parts: (1) play analysis and resource assessment, (2) reservoir characterization, and (3) development of advanced extraction technology.Bureau of Economic Geolog
Recommended from our members
State Lands Energy Resource Optimization Project
The State Lands Energy Resource Optimization (S-ERO) Project, for which the Bureau of Economic Geology is the lead contractor and coordinating institution, is a five-university consortium study of hydrocarbon resources on Texas State Lands. The five universities are The University of Texas at Austin, Texas A&M University, the University of Houston, Texas Tech University, and Lamar University, and the entire program is aided by the cooperation of the General Land Office of Texas. Project personnel include geologists, petroleum engineers, geophysicists, and chemists. The interdisciplinary nature of this project is directed toward a more thorough understanding of the geologic controls on production and the development of appropriate recovery technologies to address the specific needs of State Lands reservoirs. Transfer of these technologies to industry, in particular to independent operators, is expected to result in increased efficiency of hydrocarbon recovery from State Lands and increased revenue to the Texas Public School Fund. The project is divided into three parts: (1) play analysis and resource assessment, (2) reservoir characterization, and (3) development of advanced extraction technology. The play analysis and resource assessment part of this research program involves dividing the oil and gas fields on Texas State Lands into geologically based families, such that fields with similar depositional histories, trapping styles, production efficiencies, and extraction difficulties are grouped into "plays." Play analysis provides the framework for making a quantitative assessment of the remaining resources on State Lands. Importantly, even maturely developed oil reservoirs may still contain substantial volumes of both "mobile" oil (oil that is movable at reservoir conditions and that can be conventionally recovered) and "residual" oil (oil that requires expensive and technically complex reservoir stimulation). The relative amounts of these resource types vary among the geologically based plays. Quantifying the amounts of these two types of oil on State Lands, as well as quantifying the remaining natural gas resource, is critical both for designing field development programs and for optimizing the recovery economics of Texas hydrocarbon resources and is the focus of the resource assessment task.Bureau of Economic Geolog
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