Search Results

You are looking at 1 - 7 of 7 items for

  • Author or Editor: F. R. Moore x
Clear All Modify Search

Abstract

We tested the relationships between female status and mate preferences demonstrated in previous correlational studies in an experimental manipulation of female perceptions of the status of women. To achieve this, 147 female undergraduate students considered either the advantages (positive condition) or disadvantages (negative condition) experienced by women as a result of belonging to the female gender and reported their mate preferences. We hypothesised that women in the positive condition would exhibit less traditional mate preferences (i.e. have younger ideal partner ages and maximum and minimum partner ages tolerated and stronger preferences for cues to genetic quality relative to material resources) than those in the negative condition. Condition did not affect preferences, therefore our hypotheses were not supported. There were, however, positive relationships between number of thoughts associated with the special social treatment of women and maximum partner age tolerated and number of thoughts associated with finances and mate-choice points allocated to “physically attractive” over “hard working”. There was also an interaction between occurrence of thoughts in the special social treatment category and condition on preferences for “physically attractive” over “hard working”. We conclude that our results, while consistent with previous research, do not provide experimental support for the relationships of interest and suggest that dimension-specific manipulations (e.g. of perceptions of financial status) will provide stronger tests of hypotheses.

Restricted access

Abstract

Positive relationships between perceived intelligence, actual intelligence and facial attractiveness have been attributed to (a) an attractiveness halo effect in which attractive individuals are attributed with positive personality traits and (b) a “good genes” model of mate choice. We sought to determine whether cues to intelligence exist in the face beyond an attractiveness halo effect and to explore relationships between residual cues to intelligence and personality attributions in male and female faces. In Study 1, we attempted to parametrically manipulate the perceived intelligence of faces while controlling for attractiveness. Results demonstrated that we manipulated perceived intelligence but may not have adequately controlled for an attractiveness halo effect: faces that were manipulated to look high in perceived intelligence were rated as more attractive. In Study 2, we found perceived intelligence to be related positively to perceived friendliness and sense of humour in male and female faces and inversely to perceived dominance in female faces. Results are discussed in the context of models of “good genes” and “attractiveness halo” models of the relationships between intelligence and attractiveness.

Restricted access

Abstract  

A prompt gamma-ray neutron activation analysis (PGNAA) system was used to calibrate and validate a Monte Carlo model as a proof of principle for the quantification of chlorine in soil. First, the response of an n-type HPGe detector to point sources of 60Co and 152Eu was determined experimentally and used to calibrate an MCNP4a model of the detector. The refined MCNP4a detector model can predict the absolute peak detection efficiency within 12% in the energy range of 120–1400 keV. Second, a PGNAA system consisting of a light-water moderated 252Cf (1.06 g) neutron source, and the shielded and collimated HPGe detector was used to collect prompt gamma-ray spectra from Savannah River Site (SRS) soil spiked with chlorine. The spectra were used to calculate the minimum detectable concentration (MDC) of chlorine and the prompt gamma-ray detection probability. Using the 252Cf based PGNAA system, the MDC for Cl in the SRS soil is 4400 g/g for an 1800-second irradiation based on the analysis of the 6110 keV prompt gamma-ray. MCNP4a was used to predict the PGNAA detection probability, which was accomplished by modeling the neutron and gamma-ray transport components separately. In the energy range of 788 to 6110 keV, the MCNP4a predictions of the prompt gamma-ray detection probability were generally within 60% of the experimental value, thus validating the Monte Carlo model.

Restricted access

Summary  

This paper contains a summary of the holdup and material control and accountability (MC&A) assays conducted for the determination of highly enriched uranium (HEU) in the deactivation and decommissioning (D&D) of the Reactor Fuel Fabrication Facility at the Savannah River Site (SRS). The facility was used to fabricate HEU fuel assemblies, lithium-aluminum target tubes, neptunium assemblies, and miscellaneous components for the SRS production reactors. The facility operated for more than 35 years. During this time thousands of uranium-aluminum alloy (U-Al) production reactor fuel tubes were produced. After the facility ceased operations in 1995, all of the easily accessible U-Al was removed from the building, and only residual amounts remained. The bulk of this residue was located in the equipment that generated and handled small U-Al particles and in the exhaust systems for this equipment (e.g., chip compactor, casting furnaces, log saw, lathes A & B, cyclone separator, FreonÔcart, riser crusher, …, etc). The D&D project is likely to represent an important example for D&D activities across SRS and across the Department of Energy weapons complex. The Savannah River National Laboratory was tasked to conduct holdup assays to quantify the amount of HEU on all components removed from the facility prior to placing in solid waste containers. The 235U holdup in any single component of process equipment must not exceed 50 g in order to meet the container limit. This limit was imposed to meet criticality requirements of the low level solid waste storage vaults. Thus, the holdup measurements were used as guidance to determine if further decontamination of equipment was needed to ensure that the quantity of 235U did not exceed the 50 g limit and to ensure that the waste met the Waste Acceptance Criteria (WAC) of the solid waste storage vaults. Since HEU is an accountable nuclear material, the holdupassays and assays of recovered residue were also important for material control and accountability purposes. In summary, the results of the holdup assays were essential for determining compliance with the Waste Acceptance Criteria, Material Control & Accountability, and to ensure that administrative criticality safety controls were not exceeded. This paper discusses theg-ray assay measurements conducted and the modeling of the acquired data to obtain measured holdup in process equipment, exhaust components, and fixed geometry scrap cans. It also presents development work required to model new acquisition configurations and to adapt available instrumentation to perform the assays.

Restricted access

Abstract  

Visual Examination (VE) gloveboxes are used to remediate transuranic waste (TRU) drums at three separate facilities at the Savannah River Site. Noncompliant items are removed before the drums undergo further characterization in preparation for shipment to the Waste Isolation Pilot Plant (WIPP). Maintaining the flow of drums through the remediation process is critical to the program’s seven-days-per-week operation. Conservative assumptions are used to ensure that glovebox contamination from this continual operation is below acceptable limits. Holdup measurements using cooled HPGe spectrometers are performed in order to confirm that these assumptions are conservative. 239Pu is the main nuclide of interest; however, 241Pu, equilibrium 237Np/233Pa and 238Pu (if detected) are typically assayed. At the Savannah River National Laboratory (SRNL) facility 243,244,245Cm are also generally observed and are always reported at either finite levels or at limits of detection. A complete assay at each of the three facilities includes a measure of TRU content in the gloveboxes and HEPA filters in the glovebox exhaust. This paper includes a description of the γ-PHA acquisitions, of the modeling, and of the calculations of nuclide content. Because each of the remediation facilities is unique and ergonomically unfavorable to γ-ray acquisitions, we have constructed custom detector support devices specific to each set of acquisitions. This paper includes a description and photographs of these custom devices. The description of modeling and calculations include determination and application of container and matrix photon energy dependent absorption factors and also determination and application of geometry factors relative to our detector calibration geometry. The paper also includes a discussion of our measurements’ accuracy using off-line assays of two SRNL HEPA filters. The comparison includes assay of the filters inside of 55-gallon drums using the SRNL Q2 assay system and separately using off-line assay with an acquisition configuration unique from the original in-situ acquisitions.

Restricted access

Abstract  

A two-parameter coincident (X-ray, X-ray) measurement was made using a Si(Li) X-ray detector and a Ge(Li) X-ray detector to study the X-ray production in the252Cf fission process.K X-ray peaks from adjacentZ fission products for elements Y through Rh and I through Pr are well resolved in both detectors. The measurement yields the result that there is a large number of coincident events with X-rays from the sameZ element as well as with X-rays from the complementary fission product (e.g. CsK X-rays are in coincidence with both the complementary TcK X-rays and the CsK X-rays). The various possibilities one may consider are: (1)K X-ray production by the primary fission process followed by internal conversion, (2) multipleK X-ray production in the stopping process of the fission products, (3)K shell ionization resulting from β-decay of the fission fragments followed by internal conversion in the same fragment, and (4) multiple internal conversion processes from cascading transitions. Each of these four possible causes for self-coincident X-ray production is explored. Further two-parameter measurements were made of low-energy γ-rays in coincidence with characteristicK X-rays from the individual elements formed in the fission. Combined with previous mass determinations, it was possible to identify many of the observed γ-rays with individual isotopes. However, a large number of low-energy transitions were observed and identified as to elemental charge, but which had not been seen previously so that no mass determination was possible.

Restricted access
Authors: R. C. Moore, M. Gasser, N. Awwad, K. C. Holt, F. M. Salas, A. Hasan, M. A. Hasan, H. Zhao and C. A. Sanchez

Summary  

The MARC-VI conference served as an excellent setting for a session organized to present and discuss the problems in nuclear science manpower and education. A panel discussion and contributed papers reflected the world-wide situation. This paper presents the major points of the panel discussion. As a result, a resolution on the current situation of nuclear chemistry and radiochemistry was drafted and endorsed by the conference attendees.

Restricted access