295 research outputs found

    Happily ever after the \u27Burg

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    Negative Impacts of Mandatory Standardized Testing on Teachers and Students

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    Mandatory standardized testing was implemented in the United States to hold schools and teachers accountable for students’ growth; however, testing has negatively impacted both teachers and students in the classroom. There is currently not enough research on the benefits to testing and whether there are more effective ways to hold schools and teachers accountable. It is important to further research the effects of heavy test preparation that is done in classrooms as well as how students’ test results can be an inaccurate representation of their abilities. This project explores the negative impacts of standardized testing as well as providing a plan to address these issues

    TANK 18-F AND 19-F TANK FILL GROUT SCALE UP TEST SUMMARY

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    High-level waste (HLW) tanks 18-F and 19-F have been isolated from FTF facilities. To complete operational closure the tanks will be filled with grout for the purpose of: (1) physically stabilizing the tanks, (2) limiting/eliminating vertical pathways to residual waste, (3) entombing waste removal equipment, (4) discouraging future intrusion, and (5) providing an alkaline, chemical reducing environment within the closure boundary to control speciation and solubility of select radionuclides. This report documents the results of a four cubic yard bulk fill scale up test on the grout formulation recommended for filling Tanks 18-F and 19-F. Details of the scale up test are provided in a Test Plan. The work was authorized under a Technical Task Request (TTR), HLE-TTR-2011-008, and was performed according to Task Technical and Quality Assurance Plan (TTQAP), SRNL-RP-2011-00587. The bulk fill scale up test described in this report was intended to demonstrate proportioning, mixing, and transportation, of material produced in a full scale ready mix concrete batch plant. In addition, the material produced for the scale up test was characterized with respect to fresh properties, thermal properties, and compressive strength as a function of curing time

    Tanks 18 And 19-F Structural Flowable Grout Fill Material Evaluation And Recommendations

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    Cementitious grout will be used to close Tanks 18-F and 19-F. The functions of the grout are to: 1) physically stabilize the final landfill by filling the empty volume in the tanks with a non-compressible material; 2) provide a barrier for inadvertent intrusion into the tank; 3) reduce contaminant mobility by a) limiting the hydraulic conductivity of the closed tank and b) reducing contact between the residual waste and infiltrating water; and 4) providing an alkaline, chemically reducing environment in the closed tank to control speciation and solubility of selected radionuclides. The objective of this work was to identify a single (all-in-one) grout to stabilize and isolate the residual radionuclides in the tank, provide structural stability of the closed tank and serve as an inadvertent intruder barrier. This work was requested by V. A. Chander, High Level Waste (HLW) Tank Engineering, in HLW-TTR-2011-008. The complete task scope is provided in the Task Technical and QA Plan, SRNL-RP-2011-00587 Revision 0. The specific objectives of this task were to: 1) Identify new admixtures and dosages for formulating a zero bleed flowable tank fill material selected by HLW Tank Closure Project personnel based on earlier tank fill studies performed in 2007. The chemical admixtures used for adjusting the flow properties needed to be updated because the original admixture products are no longer available. Also, the sources of cement and fly ash have changed, and Portland cements currently available contain up to 5 wt. % limestone (calcium carbonate). 2) Prepare and evaluate the placement, compressive strength, and thermal properties of the selected formulation with new admixture dosages. 3) Identify opportunities for improving the mix selected by HLW Closure Project personnel and prepare and evaluate two potentially improved zero bleed flowable fill design concepts; one based on the reactor fill grout and the other based on a shrinkage compensating flowable fill mix design. 4) Prepare samples for hydraulic property measurements for comparison to the values in the F and H- Tank Farm Performance Assessments (PAs). 5) Identify a grout mix for the Tanks 18-F and 19-F Grout Procurement Specification [Forty, 2011 a, b, c]. Results for two flowable zero bleed structural fill concepts containing 3/8 inch gravel (70070 Series and LP#8 Series) and a sand only mix (SO Series) are provided in this report. Tank Farm Engineering and SRNL Project Management selected the 70070 mix as the base case for inclusion in Revision 0 of the Tanks 18-F and 19-F grout procurement specification [Forty 2011 a] and requested admixture recommendations and property confirmation for this formulation [Forty, 2011 b]. Lower cementitious paste mixes were formulated because the 70070 mix is over designed with respect to strength and generates more heat from hydration reactions than is desirable for mass pour application. Work was also initiated on a modification of the recommended mix which included shrinkage compensation to mitigate fast pathways caused by shrinkage cracking and poor physical bonding to the tank and ancillary equipment. Testing of this option was postponed to FY12. Mix, LP#8-16 is recommended for inclusion in the specification for furnishing and delivering tank closure grout for Tanks 18-F and 19-F [Forty, 2011 c]. A shrinkage compensating variation of this mix, LP#16C, has not been fully developed and characterized at this time

    The pleomorphic xanthoastrocytoma and its differential diagnosis: A study of five cases

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    __Abstract__ Five brain tumors with the histopathologic features of pleomorphic xanthoastrocytomas (PXAs) are presented. Computed tomography scans showed a remarkable homology. Two cases had atypical localizations for a PXA, while one 46-year-old patient did not conform to the normal age distribution of this tumor. Nevertheless, in these cases, the histopathology was always characteristic for PXA, a remarkable pleomorphism, in addition to simultaneous expression of glial fibrillary acidic protein and histiocytic markers in the various tumor cells. In one of the presented tumors, however, clusters of neoplastic neuronal cells were also found. In this particular case, differential diagnostic criteria to distinguish between a PXA and a desmoplastic infantile ganglioglioma are lacking

    Automated Control System for the Remote-Controlled Torch Positioner

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    The goal of this project is to design and implement a controls system for Dr. Morscher’s burner rig. The rig serves to simulate jet turbine conditions and test how materials, specifically ceramic matrix composites, react under high temperatures and stresses. Currently, the location of the torch relies solely on manual adjustments and has no automated control system. The improved design will automatically adjust the torch position based on the desired temperature of the sample being tested, therefore maintaining a steady environment for the sample. The current method of manual adjustments for regulating temperature is a crude solution that does not allow for specific testing conditions. We will utilize LabView to create the controls system with the input being the Forward Looking Infrared (FLIR) camera for temperature measurement, and the torch’s distance from the sample being the output. A FLIR camera mount will be modeled and produced to create a stationary position for the camera to take accurate measurements. The torch mount for this setup has already been created, including the servo motors required to move the torch. The main objective of this project is to create a controls system that will allow the mount to automatically move depending on the temperature input by the FLIR camera

    MAGNESIUM MONO POTASSIUM PHOSPHATE GROUT FOR P-REACTOR VESSEL IN-SITU DECOMISSIONING

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    The objective of this report is to document laboratory testing of magnesium mono potassium phosphate grouts for P-Reactor vessel in-situ decommissioning. Magnesium mono potassium phosphate cement-based grout was identified as candidate material for filling (physically stabilizing) the 105-P Reactor vessel (RV) because it is less alkaline than portland cement-based grout (pH of about 12.4). A less alkaline material ({<=} 10.5) was desired to address a potential materials compatibility issue caused by corrosion of aluminum metal in highly alkaline environments such as that encountered in portland cement grouts. Information concerning access points into the P-Reactor vessel and amount of aluminum metal in the vessel is provided elsewhere. Fresh and cured properties were measured for: (1) commercially blended magnesium mono potassium phosphate packaged grouts, (2) commercially available binders blended with inert fillers at SRNL, (3) grouts prepared from technical grade MgO and KH{sub 2}PO{sub 4} and inert fillers (quartz sands, Class F fly ash), and (4) Ceramicrete{reg_sign} magnesium mono potassium phosphate-based grouts prepared at Argonne National Laboratory. Boric acid was evaluated as a set retarder in the magnesium mono potassium phosphate mixes

    TANK 18 AND 19-F TIER 1A EQUIPMENT FILL MOCK UP TEST SUMMARY

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    The United States Department of Energy (US DOE) has determined that Tanks 18-F and 19-F have met the F-Tank Farm (FTF) General Closure Plan Requirements and are ready to be permanently closed. The high-level waste (HLW) tanks have been isolated from FTF facilities. To complete operational closure they will be filled with grout for the purpose of: (1) physically stabilizing the tanks, (2) limiting/eliminating vertical pathways to residual waste, (3) discouraging future intrusion, and (4) providing an alkaline, chemical reducing environment within the closure boundary to control speciation and solubility of select radionuclides. Bulk waste removal and heel removal equipment remain in Tanks 18-F and 19-F. This equipment includes the Advance Design Mixer Pump (ADMP), transfer pumps, transfer jets, standard slurry mixer pumps, equipment-support masts, sampling masts, dip tube assemblies and robotic crawlers. The present Tank 18 and 19-F closure strategy is to grout the equipment in place and eliminate vertical pathways by filling voids in the equipment to vertical fast pathways and water infiltration. The mock-up tests described in this report were intended to address placement issues identified for grouting the equipment that will be left in Tank 18-F and Tank 19-F. The Tank 18-F and 19-F closure strategy document states that one of the Performance Assessment (PA) requirements for a closed tank is that equipment remaining in the tank be filled to the extent practical and that vertical flow paths 1 inch and larger be grouted. The specific objectives of the Tier 1A equipment grout mock-up testing include: (1) Identifying the most limiting equipment configurations with respect to internal void space filling; (2) Specifying and constructing initial test geometries and forms that represent scaled boundary conditions; (3) Identifying a target grout rheology for evaluation in the scaled mock-up configurations; (4) Scaling-up production of a grout mix with the target rheology (16 second flow cone value) from 0.25 cubic feet to 4.3 cubic feet. (Ten 0.43 cubic batches were produced because full-scale equipment was not available for the Tier 1A test.); (5) Demonstrating continuous gravity filling of the ADMP mock up test form; (6) Demonstrating continuous gravity filling of 1 inch and 2 inch schedule 40 pipe; and (7) Demonstrating filling of 1 inch and 2 inch schedule 40 pipe from the bottom up by discharging through a tube inserted into the pipes. The Tier 1A mock-up test focused on the ADMP and pipes at least one inch in diameter. The ADMP which is located in center riser of Tank 18-F is a concern because the column for this long-shaft (55 ft) pump is unique and modification to the pump prior to placing it in service limited the flow path options for filling by creating a single flow path for filling and venting the ADMP support column. The large size, vertical orientation, and complicated flow path in the ADMP warrants a detailed description of this piece of ancillary equipment
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