Preventing Buoyant Displacement Gas Release Events in Hanford Double-Shell Waste Tanks

This report summarizes the predictive methods used to ensure that waste transfer operations in Hanford waste tanks do not create waste configurations that lead to unsafe gas release events. The gas release behavior of the waste in existing double-shell tanks has been well characterized, and the flammable gas safety issues associated with safe storage of waste in the current configuration are being formally resolved. However, waste is also being transferred between double-shell tanks and from single-shell tanks into double-shell tanks by saltwell pumping and sluicing that create new wastes and waste configurations that have not been studied as well. Additionally, planning is underway for various waste transfer scenarios to support waste feed delivery to the proposed vitrification plant. It is critical that such waste transfers do not create waste conditions with the potential for dangerous gas release events

Initial Investigation of Waste Feed Delivery Tank Mixing and Sampling Issues

The Hanford tank farms contractor will deliver waste to the Waste Treatment Plant (WTP) from a staging double-shell tank. The WTP broadly classifies waste it receives in terms of “Envelopes,” each with different limiting properties and composition ranges. Envelope A, B, and C wastes are liquids that can include up to 4% entrained solids that can be pumped directly from the staging DST without mixing. Envelope D waste contains insoluble solids and must be mixed before transfer. The mixing and sampling issues lie within Envelope D solid-liquid slurries. The question is how effectively these slurries are mixed and how representative the grab samples are that are taken immediately after mixing. This report summarizes the current state of knowledge concerning jet mixing of wastes in underground storage tanks. Waste feed sampling requirements are listed, and their apparent assumption of uniformity by lack of a requirement for sample representativeness is cited as a significant issue. The case is made that there is not an adequate technical basis to provide such a sampling regimen because not enough is known about what can be achieved in mixing and distribution of solids by use of the baseline submersible mixing pump system. A combined mixing-sampling test program is recommended to fill this gap. Historical Pacific Northwest National Laboratory project and tank farms contractor documents are used to make this case. A substantial investment and progress are being made to understand mixing issues at the WTP. A summary of the key WTP activities relevant to this project is presented in this report. The relevant aspects of the WTP mixing work, together with a previously developed scaled test strategy for determining solids suspension with submerged mixer pumps (discussed in Section 3) provide a solid foundation for developing a path forward

Metamagnetic Quantum Criticality

A renormalization group treatment of metamagnetic quantum criticality in metals is presented. In clean systems the universality class is found to be of the overdamped, conserving (dynamical exponent z=3) Ising type. Detailed results are obtained for the field and temperature dependence of physical quantities including the differential susceptibility, resistivity and specific heat near the transition. An application of the theory is made to Sr3Ru2O7, which appears to exhibit a metamagnetic critical end-point at a very low temperature and a field of order 5-7T.Comment: 4 pages latex (Revtex 4) and 3 eps figure

Hanford Tank Farms Waste Certification Flow Loop Test Plan

A future requirement of Hanford Tank Farm operations will involve transfer of wastes from double shell tanks to the Waste Treatment Plant. As the U.S. Department of Energy contractor for Tank Farm Operations, Washington River Protection Solutions anticipates the need to certify that waste transfers comply with contractual requirements. This test plan describes the approach for evaluating several instruments that have potential to detect the onset of flow stratification and critical suspension velocity. The testing will be conducted in an existing pipe loop in Pacific Northwest National Laboratory’s facility that is being modified to accommodate the testing of instruments over a range of simulated waste properties and flow conditions. The testing phases, test matrix and types of simulants needed and the range of testing conditions required to evaluate the instruments are describe

Metamagnetic Quantum Criticality in Sr3Ru2O7

We consider the metamagnetic transition in the bilayer ruthenate, ${\rm Sr_3Ru_2O_7}$, and use this to motivate a renormalization group treatment of a zero-temperature quantum-critical end-point. We summarize the results of mean field theory and give a pedagogical derivation of the renormalization-group equations. These are then solved to yield numerical results for the susceptibility, the specific heat and the resistivity exponent which can be compared with measured data on ${\rm Sr_3Ru_2O_7}$ to provide a powerful test for the standard framework of metallic quantum criticality. The observed approach to the critical point is well-described by our theory explaining a number of unusual features of experimental data. The puzzling behaviour very near to the critical point itself, though, is not accounted for by this, or any other theory with a Fermi surface

Type IIb Supernova SN 2011dh: Spectra and Photometry from the Ultraviolet to the Near-Infrared

We report spectroscopic and photometric observations of the Type IIb SN 2011dh obtained between 4 and 34 days after the estimated date of explosion (May 31.5 UT). The data cover a wide wavelength range from 2,000 Angstroms in the UV to 2.4 microns in the NIR. Optical spectra provide line profiles and velocity measurements of HI, HeI, CaII and FeII that trace the composition and kinematics of the SN. NIR spectra show that helium is present in the atmosphere as early as 11 days after the explosion. A UV spectrum obtained with the STIS reveals that the UV flux for SN 2011dh is low compared to other SN IIb. The HI and HeI velocities in SN 2011dh are separated by about 4,000 km/s at all phases. We estimate that the H-shell of SN 2011dh is about 8 times less massive than the shell of SN 1993J and about 3 times more massive than the shell of SN 2008ax. Light curves (LC) for twelve passbands are presented. The maximum bolometric luminosity of $1.8 \pm 0.2 \times 10^{42}$ erg s$^{-1}$ occurred about 22 days after the explosion. NIR emission provides more than 30% of the total bolometric flux at the beginning of our observations and increases to nearly 50% of the total by day 34. The UV produces 16% of the total flux on day 4, 5% on day 9 and 1% on day 34. We compare the bolometric light curves of SN 2011dh, SN 2008ax and SN 1993J. The LC are very different for the first twelve days after the explosions but all three SN IIb display similar peak luminosities, times of peak, decline rates and colors after maximum. This suggests that the progenitors of these SN IIb may have had similar compositions and masses but they exploded inside hydrogen shells that that have a wide range of masses. The detailed observations presented here will help evaluate theoretical models for this supernova and lead to a better understanding of SN IIb.Comment: 23 pages, 14 figures, 9 tables, accepted by Ap

Final Report One-Twelfth-Scale Mixing Experiments to Characterize Double-Shell Tank Slurry Uniformity

The objectives of these 1/12-scale scoping experiments were to Determine which of the dimensionless parameters discussed in Bamberger and Liljegren (1994) affect the maximum concentration that can be suspended during jet mixer pump operation in the full-scale double-shell tanks Develop empirical correlations to predict the nozzle velocity required for jet mixer pumps to suspend the contents of full-scale double-shell tanks Apply the models to predict the nozzle velocity required to suspend the contents of Tank 241 AZ-101 Obtain experimental concentration data to compare with the TEMPEST( )(Trent and Eyler 1989) computational modeling predictions to guide further code development Analyze the effects of changing nozzle diameter on exit velocity (U0) and U0D0 (the product of the exit velocity and nozzle diameter) required to suspend the contents of a tank. The scoping study experimentally evaluated uniformity in a 1/12-scale experiment varying the Reynolds number, Froude number, and gravitational settling parameter space. The initial matrix specified only tests at 100% U0D0 and 25% U0D0. After initial tests were conducted with small diameter, low viscosity simulant this matrix was revised to allow evaluation of a broader range of U0D0s. The revised matrix included full factorial test between 100% and 50% U0D0 and two half-factorial tests at 75% and 25% U0D0. Adding points at 75% U0D0 and 50% U0D0 allowed evaluation curvature. Eliminating points at 25% U0D0 decreased the testing time by several weeks. Test conditions were achieved by varying the simulant viscosity, the mean particle size, and the jet nozzle exit velocity. Concentration measurements at sampling locations throughout the tank were used to assess the degree of uniformity achieved during each test. Concentration data was obtained using a real time ultrasonic attenuation probe and discrete batch samples. The undissolved solids concentration at these locations was analyzed to determine whether the tank contents were uniform ( ±10% variation about mean) in concentration. Concentration inhomogeneity was modeled as a function of dimensionless groups. The two parameters that best describe the maximum solids volume fraction that can be suspended in a double-shell tank were found to be 1) the Froude number (Fr) based on nozzle velocity (U0) and tank contents level (H) and 2) the dimensionless particle size (dp/D0). The dependence on the Reynolds number (Re) does not appear to be statistically significant

Successful ecosystem-based management of Antarctic krill should address uncertainties in krill recruitment, behaviour and ecological adaptation

Antarctic krill, Euphausia superba, supports a valuable commercial fishery in the Southwest Atlantic, which holds the highest krill densities and is warming rapidly. The krill catch is increasing, is concentrated in a small area, and has shifted seasonally from summer to autumn/winter. The fishery is managed by the Commission for the Conservation of Antarctic Marine Living Resources, with the main goal of safeguarding the large populations of krilldependent predators. Here we show that, because of the restricted distribution of successfully spawning krill and high inter-annual variability in their biomass, the risk of direct fishery impacts on the krill stock itself might be higher than previously thought. We show how management benefits could be achieved by incorporating uncertainty surrounding key aspects of krill ecology into management decisions, and how knowledge can be improved in these key areas. This improved information may be supplied, in part, by the fishery itself

Technology-assisted stroke rehabilitation in Mexico: a pilot randomized trial comparing traditional therapy to circuit training in a Robot/technology-assisted therapy gym

Background Stroke rehabilitation in low- and middle-income countries, such as Mexico, is often hampered by lack of clinical resources and funding. To provide a cost-effective solution for comprehensive post-stroke rehabilitation that can alleviate the need for one-on-one physical or occupational therapy, in lower and upper extremities, we proposed and implemented a technology-assisted rehabilitation gymnasium in Chihuahua, Mexico. The Gymnasium for Robotic Rehabilitation (Robot Gym) consisted of low- and high-tech systems for upper and lower limb rehabilitation. Our hypothesis is that the Robot Gym can provide a cost- and labor-efficient alternative for post-stroke rehabilitation, while being more or as effective as traditional physical and occupational therapy approaches. Methods A typical group of stroke patients was randomly allocated to an intervention (n = 10) or a control group (n = 10). The intervention group received rehabilitation using the devices in the Robot Gym, whereas the control group (n = 10) received time-matched standard care. All of the study subjects were subjected to 24 two-hour therapy sessions over a period of 6 to 8 weeks. Several clinical assessments tests for upper and lower extremities were used to evaluate motor function pre- and post-intervention. A cost analysis was done to compare the cost effectiveness for both therapies. Results No significant differences were observed when comparing the results of the pre-intervention Mini-mental, Brunnstrom Test, and Geriatric Depression Scale Test, showing that both groups were functionally similar prior to the intervention. Although, both training groups were functionally equivalent, they had a significant age difference. The results of all of the upper extremity tests showed an improvement in function in both groups with no statistically significant differences between the groups. The Fugl-Meyer and the 10 Meters Walk lower extremity tests showed greater improvement in the intervention group compared to the control group. On the Time Up and Go Test, no statistically significant differences were observed pre- and post-intervention when comparing the control and the intervention groups. For the 6 Minute Walk Test, both groups presented a statistically significant difference pre- and post-intervention, showing progress in their performance. The robot gym therapy was more cost-effective than the traditional one-to-one therapy used during this study in that it enabled therapist to train up to 1.5 to 6 times more patients for the approximately same cost in the long term. Conclusions The results of this study showed that the patients that received therapy using the Robot Gym had enhanced functionality in the upper extremity tests similar to patients in the control group. In the lower extremity tests, the intervention patients showed more improvement than those subjected to traditional therapy. These results support that the Robot Gym can be as effective as traditional therapy for stroke patients, presenting a more cost- and labor-efficient option for countries with scarce clinical resources and funding. Trial registration ISRCTN98578807

Physical Activity-Related Policy and Environmental Strategies to Prevent Obesity in Rural Communities: A Systematic Review of the Literature, 2002-2013

Citation: Meyer, M. R. U., Perry, C. K., Sumrall, J. C., Patterson, M. S., Walsh, S. M., Clendennen, S. C., . . . Valko, C. (2016). Physical Activity-Related Policy and Environmental Strategies to Prevent Obesity in Rural Communities: A Systematic Review of the Literature, 2002-2013. Preventing Chronic Disease, 13, 24. doi:10.5888/pcd13.150406Additional Authors: Valko, C.Introduction Health disparities exist between rural and urban residents; in particular, rural residents have higher rates of chronic diseases and obesity. Evidence supports the effectiveness of policy and environmental strategies to prevent obesity and promote health equity. In 2009, the Centers for Disease Control and Prevention recommended 24 policy and environmental strategies for use by local communities: the Common Community Measures for Obesity Prevention (COCOMO); 12 strategies focus on physical activity. This review was conducted to synthesize evidence on the implementation, relevance, and effectiveness of physical activity-related policy and environmental strategies for obesity prevention in rural communities. Methods A literature search was conducted in PubMed, PsycINFO, Web of Science, CINHAL, and PAIS databases for articles published from 2002 through May 2013 that reported findings from physical activity-related policy or environmental interventions conducted in the United States or Canada. Each article was extracted independently by 2 researchers. Results Of 2,002 articles, 30 articles representing 26 distinct studies met inclusion criteria. Schools were the most common setting (n = 18 studies). COCOMO strategies were applied in rural communities in 22 studies; the 2 most common COCOMO strategies were "enhance infrastructure supporting walking" (n = 11) and " increase opportunities for extracurricular physical activity" (n = 9). Most studies (n = 21) applied at least one of 8 non-COCOMO strategies; the most common was increasing physical activity opportunities at school outside of physical education (n = 8). Only 14 studies measured or reported physical activity outcomes (10 studies solely used self-report); 10 reported positive changes. Conclusion Seven of the 12 COCOMO physical activity-related strategies were successfully implemented in 2 or more studies, suggesting that these 7 strategies are relevant in rural communities and the other 5 might be less applicable in rural communities. Further research using robust study designs and measurement is needed to better ascertain implementation success and effectiveness of COCOMO and non-COCOMO strategies in rural communities