177 research outputs found
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Scoping evaluation of the technical capabilities of DOE sites for disposal of hazardous metals in mixed low-level waste
A team of analysts designed and conducted a scoping evaluation to estimate the technical capabilities of fifteen Department of Energy sites for disposal of the hazardous metals in mixed low-level waste (i.e., waste that contains both low-level radioactive materials and hazardous constituents). Eight hazardous metals were evaluated: arsenic, barium, cadmium, chromium, lead, mercury, selenium, and silver. The analysis considered transport only through the groundwater pathway. The results are reported as site-specific estimates of maximum concentrations of each hazardous metal in treated mixed low-level waste that do not exceed the performance measures established for the analysis. Also reported are site-specific estimates of travel times of each hazardous metal to the point of compliance
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Analysis of the technical capabilities of DOE sites for disposal of residuals from the treatment of mixed low-level waste
The US Department of Energy (DOE) has stored or expects to generate over the next five years more than 130,000 m{sup 3} of mixed low-level waste (MLLW). Before disposal, MLLW is usually treated to comply with the land disposal restrictions of the Resource Conservation and Recovery Act. Depending on the type of treatment, the original volume of MLLW and the radionuclide concentrations in the waste streams may change. These changes must be taken into account in determining the necessary disposal capacity at a site. Treatment may remove the characteristic in some waste that caused it to be classified as mixed. Treatment of some waste may, by reduction of the mass, increase the concentrations of some transuranic radionuclides sufficiently so that it becomes transuranic waste. In this report, the DOE MLLW streams were analyzed to determine after-treatment volumes and radionuclide concentrations. The waste streams were reclassified as residual MLLW or low-level or transuranic waste resulting from treatment. The volume analysis indicated that about 89,000 m{sup 3} of waste will require disposal as residual MLLW. Fifteen DOE sites were then evaluated to determine their capabilities for hosting disposal facilities for some or all of the residual MLLW. Waste streams associated with about 90% of the total residual MLLW volume are likely to present no significant issues for disposal and require little additional analysis. Future studies should focus on the remaining waste streams that are potentially problematic by examining site-specific waste acceptance criteria, alternative treatment processes, alternative waste forms for disposal, and pending changes in regulatory requirements
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Evaluation of the capabilities of the Hanford Reservation and Envirocare of Utah for disposal of potentially problematic mixed low-level waste streams
The US Department of Energy`s (DOE) Mixed Waste Focus Area is developing a program to address and resolve issues associated with final waste form performance in treating and disposing of DOE`s mixed low-level waste (MLLW) inventory. A key issue for the program is identifying MLLW streams that may be problematic for disposal. Previous reports have quantified and qualified the capabilities of fifteen DOE sites for MLLW disposal and provided volume and radionuclide concentration estimates for treated MLLW based on the DOE inventory. Scoping-level analyses indicated that 101 waste streams identified in this report (approximately 6,250 m{sup 3} of the estimated total treated MLLW) had radionuclide concentrations that may make their disposal problematic. The radionuclide concentrations of these waste streams were compared with the waste acceptance criteria (WAC) for a DOE disposal facility at Hanford and for Envirocare`s commercial disposal facility for MLLW in Utah. Of the treated MLLW volume identified as potentially problematic, about 100 m{sup 3} exceeds the WAC for disposal at Hanford, and about 4,500 m{sup 3} exceeds the WAC for disposal at Envirocare. Approximately 7% of DOE`s total MLLW inventory has not been sufficiently characterized to identify a treatment process for the waste and was not included in the analysis. In addition, of the total treated MLLW volume, about 30% was associated with waste streams that did not have radionuclide concentration data and could not be included in the determination of potentially problematic waste streams
Boraformylation and Silaformylation of Allenes
The boraformylation of allenes with B2(pin)2 and a formate ester as boron and formyl source, respectively, proceeds in the presence of a copper catalyst. The reaction selectively affords the corresponding β‐boryl β,γ‐unsaturated aldehydes in good to high yields. Furthermore, the silaformylation of allenes was achieved with a formate ester and PhMe2Si−B(pin) as the silicon source.Boron or silicon? Boraformylation and silaformylation reactions of allenes with formate esters smoothly proceed in the presence of a copper catalyst using B2(pin)2 and PhMe2Si−B(pin) as the boron and silicon source, respectively. These reactions selectively afford the corresponding β‐boryl and β‐silyl β,γ‐unsaturated aldehydes in good to high yields with excellent regioselectivity.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137579/1/anie201611314-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137579/2/anie201611314_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137579/3/anie201611314.pd
Erkenntnisse zum mechanischen Messingreibebeschichten bei der Zylinder/Kolbenring-Werkstoffpaarung in Verbrennungsmotoren
ChemInform Abstract: Uses of Silicon-Containing Compounds in the Synthesis of Natural Products
Two novel HMW MAP2 variants with four microtubule-binding repeats and different projection domains
AbstractThe brain microtubule-associated protein MAP2 is composed of two high molecular (MAP2a and b) and one low molecular (MAP2c) weight isoforms. All these forms were thought to contain three repeated microtubule-binding domains in their C-terminal region but a MAP2c variant containing four repeats has recently been identified. We report here the existence of two high molecular weight MAP2 isoforms with four microtubule-binding domains in the sensory neuronal cell line ND 7/23. A stretch of 135 bp is missing in one of these forms suggesting that several HMW MAP2 variants can be produced by alternative splicing
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