[en] It is shown how the attitudes of extremists, conservationists, supporters of Aboriginal land claims and opponents of uranium mining have affected those who are influential in determining how Australians view the mining and in particular, uranium mining. The author also tells the story of the discovery of the Olympic Dam and shows how the people involved with Olympic Dam are passionate and proud about their work. ills

[en] From 1943 through 1986, Battelle Memorial Institute (BMI) performed research and development work at its own facilities for the U.S. Department of Energy (DOE) and its predecessor agencies. The most highly contaminated facilities, comprising BMI's Nuclear Sciences Area, are located on 11 acres in West Jefferson, Ohio. Three buildings in this area were used to study nuclear reactor fuels, fuel element components, reactor designs, and radiochemistry analyses: one building contained nuclear hot cells, a second building contained a critical assembly and radiochemistry laboratory, and a third building once housed a nuclear research reactor. The Columbus Environmental Management Project (CEMP), one of the DOE Ohio Field Office's radioactive cleanup sites, oversees the Battelle Columbus Laboratories Decommissioning Project (BCLDP) for the decontamination and decommissioning (D and D) of BMI's Nuclear Sciences Area. The BCLDP mission is to decontaminate the Nuclear Sciences Area to a condition that is suitable for use without restrictions and to dispose of or store the associated radioactive waste at a suitable DOE-approved facility. During decontamination work, the CEMP is expected to generate approximately 120, 55-gallon drums of transuranic (TRU) waste, or about 20 truckloads. This TRU waste will be transported to DOE's Hanford nuclear facility in Washington State for temporary storage, prior to its ultimate disposal at the Waste Isolation Pilot Plant (WIPP). This paper presents a detailed approach for conducting readiness assessments for TRU waste shipments from any DOE site. It is based on demonstrating satisfaction of the 18 core requirements contained in DOE Order 425.1B, Startup and Restart of Nuclear Facilities, that are derived from the seven guiding principles of DOE's integrated safety management system

[en] The need for increased sensitivity in the detection of metallic contamination, in microelectronics fabrication, led to the development of heavy ion backscattering spectrometry (HIBS). This technique, based on principles similar to those of Rutherford backscattering spectrometry, permits one to quantitatively detect heavy impurities, at a level below 1 x 10¹⁰ atoms/cm², on the surface of an otherwise clean silicon substrate. The approach was developed at Sandia National Laboratories, in collaboration with SEMATECH member companies, and Vanderbilt University. Recently, the HIBS instrument was transferred to the Department of Physics of the University of Central Florida, with the purpose of continuing the development of this unique resource, and making it available to industrial and academic investigators. The instrument has been successfully returned to operation, and preliminary tests showed sensitivity levels similar to those obtained at Sandia. A program is being developed to further increase the sensitivity of the instrument, as well as to explore potential new applications. A progress report of these efforts is presented

[en] The purpose of the study was to evaluate the extent of intratumoral heterogeneity of radiation sensitivity in malignant gliomas, by comparing the intrinsic radiation sensitivity of different glioma sublines derived from the same tumor. The study was performed on five early established malignant gliomas (passage 3-10). Each specimen was quickly cut into three equal pieces (except for one specimen, where only two pieces were obtained). Each piece was processed independently, disintegrated into single cell suspension using a cocktail of enzymes. Survival curve assays, using colony formation as an end-point, were performed for each subline. Comparison between the intrinsic radiation sensitivity of sublines was calculated using the surviving fraction at 2 Gy and the mean inactivation dose as the measured parameters. The DNA content of the cell lines as well as their cell cycle analysis was determined using flow cytometry. The mean calculated surviving fraction at 2 Gy of all the sublines was 0.37, the mean mean inactivation dose was 1.98. The intertumoral coefficient of variation for the calculated surviving fraction at a statistically significant difference in the surviving fraction at 2 Gy and mean inactivation dose values of their sublines. This difference in radiation sensitivity between sublines of the same tumor was not attributed to a difference either in the ploidy status or in the distribution of cells in the cell cycle. There is a significant intratumoral heterogeneity of radiation sensitivity in some malignant gliomas. This heterogeneity may limit the predictive power of surviving fraction at 2 Gy or mean inactivation dose, especially when their values are based upon a single measurement/single biopsy. In the meantime, this heterogeneity may be a factor in the discrepancy between unexpectedly sensitive tumor cell lines in vitro and their high clinical radiation resistance. 20 refs., 3 figs., 2 tabs

[en] The authors describe their design of a liquid helium temperature prototype secondary mirror assembly (PSMA) under development for the NASA Space Infrared Telescope Facility (SIRTF) program. The SIRTF secondary mirror assembly must operate below 4 K and provide the functions of highly precise 2-axis dynamic tilting (chopping) in addition to the conventional functions needed by the SIRTF observatory. Their PSMA design employs a fused quartz mirror kinematically attached at its center to an aluminium cruciform. The mirror/cruciform assembly is driven in tilt about its combined center of mass using a unique flexure pivot and a four-actuator control system with feedback provided by pairs of differential position sensors. The voice coil actuators are mounted on a second flexure-pivoted mass enhancing servo system stability and isolating the telescope from vibration-induced disturbances. The mirror/cruciform and the reaction mass are attached to opposite sides of an aluminum mounting plate whose dimensional characteristics are nominally identical to that of the aluminum flexure pivot material. The mounting plate is connected to the outer housing by a six degree of freedom focus and centering mechanism using pivoted actuation levers driven by lead screw/harmonic drive/stepper motor assemblies

[en] Purpose/Objective: Over the last decade, there has been increasing interest in several radiobiological parameters as predictors of tumor response to radiation. Each parameter was evaluated alone. The clinical outcome was correlated and the results were mixed. In this study, we evaluated several parameters in the same tumor as predictors of response to fractionated irradiation of nine human xenografts. Methods and Materials: The fractionated TCD₅₀ (the dose of radiation which controls 50% of the tumors) using 30 fractions in 15 days of nine human tumor xenografts were determined. The tumors were implanted in the hindleg of nude mice. The parameters pO₂, IFP (interstitial fluid pressure), T_pot, SF₂, D_o, GSH, TCD₅₀ single dose in oxic and hypoxic conditions, the rate of metastasis in SCID mice and the TD₅₀ (the number of cells which induced tumors in 50% of the animals) were evaluated. The hypoxic fraction was also calculated. Results: Five glioblastoma, two squamous, one sarcoma and one colon cancer xenografts were studied. When each parameter was considered alone, none of the parameters investigated correlated with the fractionated TCD₅₀. No correlation was found between the hypoxic fraction calculated from the TCD₅₀ under oxic and hypoxic conditions and the pO₂ values for the same tumor. None of the parameters evaluated predicted the metastatic potential of these xenografts. Conclusion: These data suggest that one parameter could not predict the fractionated TCD₅₀ and that the response of human tumor xenografts to irradiation is multifactorial

[en] Purpose/Objective: Glioblastoma Multiforme (GBM) is a highly malignant tumor of the central nervous system with aggressive biological behavior and a fatal clinical outcome. Several radiobiological parameters might contribute to these poor results. In this study, we investigated seventeen biological parameters of four GBM xenografts and compared the results with four other histological types of human tumor xenografts in nude mice. Methods and Materials: Most of the xenografts retained the individual histological features of their original tumor types. Four GBM xenografts (U87, HP555, MMC1 and HGL21), two squamous cell carcinomas (SCC21 and FaDu), one soft tissue sarcoma (STS26T), and colon cancer (HCT15) xenografts were used. The tumors were implanted in the hindleg of 5-6 Gy WBI nude mice. The following parameters were investigated for most of the xenografts: fractionated TCD₅₀ (the dose of radiation which controls 50% of the tumors) using 30 fractions in 15 days. The parameters pO₂, IFP (interstitial fluid pressure), T_pot, SF₂ (plastic and Courtenay), PE (plating efficiency), D₀, GSH, TCD₅₀ single dose in oxic and hypoxic conditions, the rate of metastasis in SCID mice, VDT (volume doubling time), spontaneous apoptosis, induced apoptosis after 30 and 60 Gy and p53 over-expression. Results: Using the t-test, there was a significantly less spontaneous apoptosis in GBM xenografts when compared with the other histological types. However, no significant difference was found between both groups of xenografts in the remaining biological parameters investigated. Conclusion: These data demonstrate that, with the exception of spontaneous apoptosis, no significant difference was found in fifteen biological parameters between GBM xenografts and the other histological types implanted into the subcutaneous tissue of nude mice. The data suggests that the classical radiobiological parameters cannot explain the poor response of GBM to radiation. Supported by NCI Grant CA13311 awarded by DHHS

[en] The purpose of this work is to present alternative power conversion techniques for an energy harvester optimized to the power requirements of an activity monitoring device. Many energy harvesters designed to use human motion provide a pulsed type of output waveform, as the signal will be strongly related to the pattern of motion used for harvesting energy. Due to this type of discontinuous signal it is considered that wearable sources have the potential to provide higher energy values by pulses rather than continuous form. For this work an electromagnetic generator system was optimised to power a monitoring device located in the shoe. Rectification techniques as well as coil parameters design have been employed and powering conditions have been analysed. The generator system can provide pulses of power high enough to sustain a low power consumption device

[en] This study investigates several sources of uncertainty associated with the application of optically stimulated luminescence (OSL) to personal dosimetry. A commercial OSL system based on Al₂O₃:C was used for this study. First, it is demonstrated that the concept of repeated evaluation (readout) of the same dosemeter, often referred to as 're-analysis', can introduce uncertainty in the re-estimated dose. This uncertainty is associated with the fact that the re-analysis process depletes some of the populated traps, resulting in a continuous decrease of the OSL signal with each repeated reading. Furthermore, the rate of depletion may be dose-dependent. Second, it is shown that the previously reported light-induced fading in this system is the result of light leaks through miniature openings in the dosemeter badge. (authors)

[en] We are reporting the results of an investigation designed to determine the magnitude of the light induced fading associated with the OSL response of Al₂O₃:C. Unlike previous studies where bare, radiation sensitive OSL elements were exposed directly to light, most of the experiments described here were conducted using sealed commercially available OSL dosimeters. During light exposure the OSL sensitive elements were kept inside a standard commercially available plastic badge. A commercial OSL system was used for these experiments in an attempt to simulate typical field use conditions. Both light induced signal and light induced fading were considered, however no measurable light induced signal could be identified. Light induced fading effects, however, were significant, up to 55% loss of OSL signal following daylight exposure of 45 days. The possibility that dose information may be easily erased, intentionally or accidentally, could impose significant restrictions on the ability of the US Navy to defend, if needed, the reported personnel dose levels.