39 research outputs found
Strong-Sludge Gas Retention and Release Mechanisms in Clay Simulants
The Hanford Site has 28 double-shell tanks (DSTs) and 149 single-shell tanks (SSTs) containing radioactive wastes that are complex mixes of radioactive and chemical products. The mission of the Department of Energy's River Protection Project is to retrieve and treat the Hanford tank waste for disposal and close the tank farms. A key aspect of the mission is to retrieve and transfer waste from the SSTs, which are at greater risk for leaking, into DSTs for interim storage until the waste is transferred to and treated in the Waste Treatment and Immobilization Plant. There is, however, limited space in the existing DSTs to accept waste transfers from the SSTs, and approaches to overcoming the limited DST space will benefit the overall mission. The purpose of this study is to summarize and analyze the key previous experiment that forms the basis for the relaxed controls and to summarize progress and results on new experiments focused on understanding the conditions that result in low gas retention. The previous large-scale test used about 50 m3 of sediment, which would be unwieldy for doing multiple parametric experiments. Accordingly, experiments began with smaller-scale tests to determine whether the desired mechanisms can be studied without the difficulty of conducting very large experiments. The most significant results from the current experiments are that progressively lower gas retention occurs in tests with progressively deeper sediment layers and that the method of gas generation also affects the maximum retention. Based on the results of this study, it is plausible that relatively low gas retention could occur in sufficiently deep tank waste in DSTs. The current studies and previous work, however, have not explored how gas retention and release will behave when two or more layers with different properties are present
Modeling methanogenesis with a genome-scale metabolic reconstruction of Methanosarcina barkeri
We present a genome-scale metabolic model for the archaeal methanogen Methanosarcina barkeri. We characterize the metabolic network and compare it to reconstructions from the prokaryotic, eukaryotic and archaeal domains. Using the model in conjunction with constraint-based methods, we simulate the metabolic fluxes and resulting phenotypes induced by different environmental and genetic conditions. This represents the first large-scale simulation of either a methanogen or an archaeal species. Model predictions are validated by comparison to experimental growth measurements and phenotypes of M. barkeri on different substrates. The predicted growth phenotypes for wild type and mutants of the methanogenic pathway have a high level of agreement with experimental findings. We further examine the efficiency of the energy-conserving reactions in the methanogenic pathway, specifically the Ech hydrogenase reaction, and determine a stoichiometry for the nitrogenase reaction. This work demonstrates that a reconstructed metabolic network can serve as an analysis platform to predict cellular phenotypes, characterize methanogenic growth, improve the genome annotation and further uncover the metabolic characteristics of methanogenesis
Treatability Test Plan for an In Situ Biostimulation Reducing Barrier
This treatability test plan supports a new, integrated strategy to accelerate cleanup of chromium in the 100 Areas at the Hanford Site. This plan includes performing a field-scale treatability test for bioreduction of chromate, nitrate, and dissolved oxygen. In addition to remediating a portion of the plume and demonstrating reduction of electron acceptors in the plume, the data from this test will be valuable for designing a full-scale bioremediation system to apply at this and other chromium plumes at the Hanford Site
Recommended from our members
Science To Support DOE Site Cleanup: The Pacific Northwest National Laboratory Environmental Management Science Program Awards
Pacific Northwest National Laboratory (PNNL) was awarded ten Environmental Management Science Program (EMSP) research grants in fiscal year 1996, six in fiscal year 1997, nine in fiscal year 1998, seven in fiscal year 1999, and five in fiscal year 2000. All of the fiscal year 1996 award projects have published final reports. The 1997 and 1998 award projects have been completed or are nearing completion. Final reports for these awards will be published, so their annual updates will not be included in this document. This section summarizes how each of the 1999 and 2000 grants address significant U.S. Department of Energy (DOE) cleanup issues, including those at the Hanford Site. The technical progress made to date in each of these research projects is addressed in more detail in the individual progress reports contained in this document. The 1999 and 2000 EMSP awards at PNNL are focused primarily in two areas: Tank Waste Remediation, and Soil and Groundwater Cleanup
WSES Jerusalem guidelines for diagnosis and treatment of acute appendicitis
Acute appendicitis (AA) is among the most common cause of acute abdominal pain. Diagnosis of AA is challenging; a variable combination of clinical signs and symptoms has been used together with laboratory findings in several scoring systems proposed for suggesting the probability of AA and the possible subsequent management pathway. The role of imaging in the diagnosis of AA is still debated, with variable use of US, CT and MRI in different settings worldwide. Up to date, comprehensive clinical guidelines for diagnosis and management of AA have never been issued. In July 2015, during the 3rd World Congress of the WSES, held in Jerusalem (Israel), a panel of experts including an Organizational Committee and Scientific Committee and Scientific Secretariat, participated to a Consensus Conference where eight panelists presented a number of statements developed for each of the eight main questions about diagnosis and management of AA. The statements were then voted, eventually modified and finally approved by the participants to The Consensus Conference and lately by the board of co-authors. The current paper is reporting the definitive Guidelines Statements on each of the following topics: 1) Diagnostic efficiency of clinical scoring systems, 2) Role of Imaging, 3) Non-operative treatment for uncomplicated appendicitis, 4) Timing of appendectomy and in-hospital delay, 5) Surgical treatment 6) Scoring systems for intra-operative grading of appendicitis and their clinical usefulness 7) Non-surgical treatment for complicated appendicitis: abscess or phlegmon 8) Pre-operative and post-operative antibiotics.Peer reviewe
Recommended from our members
Integrated Field, Laboratory, and Modeling Studies to Determine the Effects of Linked Microbial and Physical Spatial Heterogeneity on Engineered Vadose Zone Bioremediation
The objective of the project at large was to experiment with new methods for bioremediation of carbon tetrachloride plumes in the soils at the Hanford Site in Richland, WA. Traditionally, biostimulation occurs via pumping of liquid nutrient solution into the vadose zone, however an alternate methodology utilizes the introduction of gaseous nutrients, specifically nitrogen, phosphorus and carbon sources. The movement of liquid through the vadose zone tends to disperse contaminant plumes, and/or cause biofouling (excessive microbial growth) in the vicinity of injection wells. Alternatively, gas-phase nutrient introduction yields greater dispersion of molecules and little to no displacement of target plumes. Once vapor-phase molecules solubilize into soil water, they become bioavailable and should thus encourage colonization and degradation. The feasibility of this method of nutrient delivery was studied in an experimental laboratory system, the goal of which was to observe, in situ, microbial colonization in response to gaseous nutrient injection. It was hoped that these observations would aid in predictive modeling of microbial behavior in field scale bioremediation
You can look and you can listen but M-U-M is the word.
Gift of Dr. Mary Jane Esplen.Piano vocal [instrumentation]Tom White grew tired of simple life tho' he was newly wed [first line]You can look and you can listen but M-U-M is the word [first line of chorus]G major [key]Moderato [tempo]Popular song [form/genre
Embedded Real-time HD Video Deblurring
Abstract-This paper explores a computational deblurring algorithm that will ultimately be implemented in an embedded system with a targeted form factor of 2"x2"x3". The deblurring algorithm completes a Fourier filtering step followed by a wavelet transform denoising step on a 1080x1920 Bayer input 30 frame per second video feed. A major challenge in performing this processing in real time is that the wavelet denoising process utilizes the stationary wavelet transform, thus exploding the bandwidth requirements of the algorithm. To reach the desired form-factor and performance rate, a hardware accelerator is required. While both GPU and FPGA implementations have been pursued, this paper limits itself to describing our successful implementation using a desktop GPU card. Additionally, we briefly highlight methods, left for future work, for improving GPU performance based on our FPGA implementation efforts that should aid in scaling from our current desktop implementation to an embedded implementation