Development of a waste dislodging and retrieval system for use in the Oak Ridge National Laboratory gunite tank

As part of the Gunite And Associated Tanks (GAAT) Treatability Study the Oak Ridge National Laboratory (ORNL) has developed a tank waste retrieval system capable of removing wastes varying from liquids to thick sludges. This system is also capable of scarifying concrete walls and floors. The GAAT Treatability Study is being conducted by the Department of Energy Oak Ridge Environmental Restoration Program. Much of the technology developed for this project was cosponsored by the DOE Office of Science and Technology through the Tanks Focus Area (TFA) and the Robotics Technology Development Program. The waste dislodging and conveyance (WD&C) system was developed jointly by ORNL and participants from the TFA. The WD&C system is comprised of a four degree-of-freedom arm with back driveable motorized joints. a cutting and dislodging tool, a jet pump and hose management system for conveyance of wastes, confined sluicing end-effector, and a control system, and must be used in conjunction with a robotic arm or vehicle. Other papers have been submitted to this conference describing the development and operation of the arm and vehicle positioning systems. This paper will describe the development of the WD&C system and its application for dislodging and conveyance of ORNL sludges from the GAAT tanks. The confined sluicing end-effector relies on medium pressure water jets to dislodge waste that is then pumped by the jet pump through the conveyance system out of the tank. This paper will describe the results of cold testing of the integrated system. At the conference presentation there will also be results from the field deployment. ORNL has completed fabrication of the WD&C system for waste removal and is full-scale testing, including testing of the confined sluicing end-effector

Inelastic X-ray scattering study of the collective dynamics in liquid sodium

Inelastic X-ray scattering data have been collected for liquid sodium at T=390 K, i.e. slightly above the melting point. Owing to the very high instrumental resolution, pushed up to 1.5 meV, it has been possible to determine accurately the dynamic structure factor, $S(Q,\omega)$, in a wide wavevector range, $1.5 \div 15$ nm$^{-1}$, and to investigate on the dynamical processes underlying the collective dynamics. A detailed analysis of the lineshape of $S(Q,\omega)$, similarly to other liquid metals, reveals the co-existence of two different relaxation processes with slow and fast characteristic timescales respectively. The present data lead to the conclusion that: i) the picture of the relaxation mechanism based on a simple viscoelastic model fails; ii) although the comparison with other liquid metals reveals similar behavior, the data do not exhibit an exact scaling law as the principle of corresponding state would predict.Comment: RevTex, 7 pages, 6 eps figures. Accepted by Phys. Rev.

Charge-separated atmospheric neutrino-induced muons in the MINOS far detector

We found 140 neutrino-induced muons in 854.24 live days in the MINOS far detector, which has an acceptance for neutrino-induced muons of 6.91 x 10{sup 6} cm{sup 2} sr. We looked for evidence of neutrino disappearance in this data set by computing the ratio of the number of low momentum muons to the sum of the number of high momentum and unknown momentum muons for both data and Monte Carlo expectation in the absence of neutrino oscillations. The ratio of data and Monte Carlo ratios, R, is R = 0.65{sub 0.12}{sup +0.15}(stat) {+-} 0.09(syst), a result that is consistent with an oscillation signal. A fit to the data for the oscillation parameters sin{sup 2} 2{theta}{sub 23} and {Delta}m{sub 23}{sup 2} excludes the null oscillation hypothesis at the 94% confidence level. We separated the muons into {mu}{sup -} and {mu}{sup +} in both the data and Monte Carlo events and found the ratio of the total number of {mu}{sup -} to {mu}{sup +} in both samples. The ratio of those ratios, {cflx R}{sub CPT}, is a test of CPT conservation. The result {cflx R}{sub CPT} = 0.72{sub -0.18}{sup +0.24}(stat){sub -0.04}{sup +0.08}(syst), is consistent with CPT conservation

Designing strategies for integrated control of ticks and tick-borne diseases at the farm level in a mixed crop-livestock system in Uganda

Ticks and tickborne diseases (TTBD) are serious animal health constraints in Uganda and acaricides are the current method of choice for their control. Although widely used, the external-input, single-technology paradigm of chemical control is unsustainable and may inhibit endemic stability. TTBD control could benefit from ecologically-based integrated pest management (IPM), which relies heavily on renewable resources administered in an integrated manner, natural mortality factors and control tactics that disrupt these factors as little as possible. Based on information generated during a preliminary survey, this paper outlines a fiamework for designing IPM strategies for TTBDs

Remote systems for waste retrieval from the Oak Ridge National Laboratory gunite tanks

As part of a Comprehensive Environmental Response, Compensation, and Liability Act Treatability Study funded by the Department of Energy, the Oak Ridge National Laboratory (ORNL) is preparing to demonstrate and evaluate two approaches for the remote retrieval of wastes in underground storage tanks. This work is being performed to identify the most cost-effective and efficient method of waste removal before full-scale remediation efforts begin in 1998. System requirements are based on the need to dislodge and remove sludge wastes ranging in consistency from broth to compacted clay from Gunite (Shotcrete) tanks that are approaching fifty years in age. Systems to be deployed must enter and exit through the existing 0.6 m (23.5 in.) risers and conduct retrieval operations without damaging the layered concrete walls of the tanks. Goals of this project include evaluation of confined sluicing techniques and successful demonstration of a telerobotic arm-based system for deployment of the sluicing system. As part of a sister project formed on the Old Hydrofracture Facility tanks at ORNL, vehicle-based tank remediation will also be evaluated

Human-specific regulation of neural maturation identified by cross-primate transcriptomics

International audienceUnique aspects of human behavior are often attributed to differences in the relative size and organization of the human brain: these structural aspects originate during early development. Recent studies indicate that human neurodevelopment is considerably slower than that in other nonhuman primates, a finding that is termed neoteny. One aspect of neoteny is the slow onset of action potentials. However, which molecular mechanisms play a role in this process remain unclear. To examine the evolutionary constraints on the rate of neuronal maturation, we have generated transcriptional data tracking five time points, from the neural progenitor state to 8-week-old neurons, in primates spanning the catarrhine lineage, including Macaca mulatta, Gorilla gorilla, Pan paniscus, Pan troglodytes, and Homo sapiens. Despite finding an overall similarity of many transcriptional signatures, species-specific and clade-specific distinctions were observed. Among the genes that exhibited human-specific regulation, we identified a key pioneer transcription factor, GATA3, that was uniquely upregulated in humans during the neuronal maturation process. We further examined the regulatory nature of GATA3 in human cells and observed that downregulation quickened the speed of developing spontaneous action potentials, thereby modulating the human neotenic phenotype. These results provide evidence for the divergence of gene regulation as a key molecular mechanism underlying human neoteny