Accelerating the Loop Expansion (open access)

Accelerating the Loop Expansion

This thesis introduces a new non-perturbative technique into quantum field theory. To illustrate the method, I analyze the much-studied phi/sup 4/ theory in two dimensions. As a prelude, I first show that the Hartree approximation is easy to obtain from the calculation of the one-loop effective potential by a simple modification of the propagator that does not affect the perturbative renormalization procedure. A further modification then susggests itself, which has the same nice property, and which automatically yields a convex effective potential. I then show that both of these modifications extend naturally to higher orders in the derivative expansion of the effective action and to higher orders in the loop-expansion. The net effect is to re-sum the perturbation series for the effective action as a systematic ''accelerated'' non-perturbative expansion. Each term in the accelerated expansion corresponds to an infinite number of terms in the original series. Each term can be computed explicitly, albeit numerically. Many numerical graphs of the various approximations to the first two terms in the derivative expansion are given. I discuss the reliability of the results and the problem of spontaneous symmetry-breaking, as well as some potential applications to more interesting field theories. 40 refs.
Date: July 29, 1986
Creator: Ingermanson, R.
System: The UNT Digital Library
Comparison of destructive and nondestructive assay of heterogeneous salt residues (open access)

Comparison of destructive and nondestructive assay of heterogeneous salt residues

To study problems associated with nondestructive assay (NDA) measurements of molten salt residues, a joint study was conducted by the Rocky Flats Plant, Golden, CO and Mound Laboratories, Miamisburg, OH. Extensive NDA measurements were made on nine containers of molten salt residues by both Rocky Flats and Mound followed by dissolution and solution quantification at Rocky Flats. Results of this study verify that plutonium and americium can be measured in such salt residues by a new gamma-ray spectral analysis technique coupled with calorimetry. Biases with respect to the segmented gamma-scan technique were noted.
Date: March 29, 1986
Creator: Fleissner, J.G. & Hume, M.W.
System: The UNT Digital Library
Summary of All Reported Accidents in the State of Texas for Calendar Year 1985 (open access)

Summary of All Reported Accidents in the State of Texas for Calendar Year 1985

Annual report providing tabular statistical information about motor vehicle accidents in Texas during calendar year 1985, with data broken out by various criteria including number of persons, locations, types of accidents, time of day, and other factors.
Date: February 29, 1986
Creator: Texas. Department of Public Safety. Statistical Services.
System: The Portal to Texas History
Texas Broilers: For Week Ending January 25, 1986 (open access)

Texas Broilers: For Week Ending January 25, 1986

Weekly report of the Texas Crop and Livestock Reporting Service on broiler chick numbers in Texas and compared with other states. It includes compiled statistics across six consecutive weeks, the week ending December 21 to the week ending January 25, during 1984, 1985, and 1986 for broiler eggs set, chicks hatched, and chicks placed.
Date: January 29, 1986
Creator: Texas Crop and Livestock Reporting Service
System: The Portal to Texas History
Texas Broilers: For Week Ending October 25, 1986 (open access)

Texas Broilers: For Week Ending October 25, 1986

Weekly report of the Texas Agricultural Statistics Service on broiler chick numbers in Texas and compared with other states. It includes compiled statistics across six consecutive weeks, from the week ending September 20 to the week ending October 25, during 1985 and 1986 for broiler eggs set, chicks hatched, and chicks placed.
Date: October 29, 1986
Creator: Texas Agricultural Statistics Service
System: The Portal to Texas History