Advanced Simulation Capability for Environmental Management (ASCEM)

2011 ◽  
Author(s):  
Paul Dixon ◽  
Mark Williamson ◽  
Mark Freshley ◽  
David Moulton ◽  
Ian Gorton ◽  
...  
Keyword(s):  
Environmental Management ◽  
The United States ◽  
Cementitious Materials ◽  
United States Department ◽  
Environmental Cleanup ◽  
Engineered Systems ◽  
The Cost ◽  
Contaminant Fate And Transport ◽  
Long Term Performance ◽  
Term Performance

The United States Department Energy (DOE) Office of Environmental Management (EM) determined that uniform application of advanced modeling in the subsurface could help reduce the cost and risks associated with its environmental cleanup mission. In response to this determination, the EM Office of Technology Innovation and Development (OTID), Groundwater and Soil Remediation (GW&S) began the program Advanced Simulation Capability for Environmental Management (ASCEM). ASCEM is a state-of-the-art scientific tool and approach for integrating data and scientific understanding to enable prediction of contaminant fate and transport in natural and engineered systems. This initiative supports the reduction of uncertainties and risks associated with EM’s environmental cleanup and closure programs through better understanding and quantifying the subsurface flow and contaminant transport behavior in complex geological systems. This involves the long-term performance of engineered components, including cementitious materials in nuclear waste disposal facilities that may be sources for future contamination of the subsurface. This paper describes the ASCEM tools and approach and the ASCEM programmatic accomplishments completed in 2010 including recent advances and technology transfer.

Demonstrating Nutrient Cost Gradients: A Brooklyn Case Study

2014 ◽  
Vol 84 (5-6) ◽  
pp. 244-251 ◽  
Author(s):  
Robert J. Karp ◽  
Gary Wong ◽  
Marguerite Orsi
Keyword(s):  
Low Income ◽  
Energy Content ◽  
Food Selection ◽  
The United States ◽  
United States Department ◽  
Micronutrient Deficiencies ◽  
Caloric Density ◽  
Low Income Families ◽  
The Cost ◽  
The Impact

Abstract. Introduction: Foods dense in micronutrients are generally more expensive than those with higher energy content. These cost-differentials may put low-income families at risk of diminished micronutrient intake. Objectives: We sought to determine differences in the cost for iron, folate, and choline in foods available for purchase in a low-income community when assessed for energy content and serving size. Methods: Sixty-nine foods listed in the menu plans provided by the United States Department of Agriculture (USDA) for low-income families were considered, in 10 domains. The cost and micronutrient content for-energy and per-serving of these foods were determined for the three micronutrients. Exact Kruskal-Wallis tests were used for comparisons of energy costs; Spearman rho tests for comparisons of micronutrient content. Ninety families were interviewed in a pediatric clinic to assess the impact of food cost on food selection. Results: Significant differences between domains were shown for energy density with both cost-for-energy (p < 0.001) and cost-per-serving (p < 0.05) comparisons. All three micronutrient contents were significantly correlated with cost-for-energy (p < 0.01). Both iron and choline contents were significantly correlated with cost-per-serving (p < 0.05). Of the 90 families, 38 (42 %) worried about food costs; 40 (44 %) had chosen foods of high caloric density in response to that fear, and 29 of 40 families experiencing both worry and making such food selection. Conclusion: Adjustments to USDA meal plans using cost-for-energy analysis showed differentials for both energy and micronutrients. These differentials were reduced using cost-per-serving analysis, but were not eliminated. A substantial proportion of low-income families are vulnerable to micronutrient deficiencies.

scholarly journals Preparation, Physicochemical Properties, and Long-Term Performance of Photocatalytic Ceramsite Sand in Cementitious Materials

2017 ◽  
Vol 7 (8) ◽  
pp. 828 ◽  
Author(s):  
Du Zhao ◽  
Fazhou Wang ◽  
Peng Liu ◽  
Lu Yang ◽  
Shuguang Hu ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Cementitious Materials ◽  
Long Term Performance ◽  
Term Performance

Advanced Techniques for Establishing Long-Term Performance of Composite Repair Systems

2014 ◽  
Author(s):  
Chris Alexander
Keyword(s):  
The United States ◽  
Operating Conditions ◽  
Repair System ◽  
Composite Repair ◽  
Design Life ◽  
Repair Systems ◽  
Long Term Performance ◽  
Term Performance ◽  
Composite Repairs

Although composite materials are used to repair and reinforce a variety of anomalies in high pressure transmission gas and liquid pipelines, there continues to be widespread debate regarding what constitutes a long-term composite repair. The United States regulations require that composite repairs must be able to permanently restore the serviceability of the repaired pipeline, while in contrast the Canadian regulations take a more prescriptive approach by integrating the ASME PCC-2 and ISO 24817 composite repair standards along with a requirement for establishing a 50-year design life. In this paper the author provides a framework for what should be considered in qualifying a composite repair system for long-term performance by focusing on the critical technical aspects associated with a sound composite repair. The presentation includes a discussion on establishing an appropriate composite design stress using the existing standards, using full-scale testing to ensure that stresses in the repair do not exceed the designated composite design stresses, and guidance for operators in how to properly integrate their pipeline operating conditions to establish a design life. By implementing the recommendations presented in this paper, operators will be equipped with a resource for objectively evaluating the composite repair systems used to repair their pipeline systems.

Grouted Waste Leach Tests: Pursuit of Mechanisms and Data for Long-Term Performance Assessment

1989 ◽  
Vol 176 ◽  
Author(s):  
R. Jeff Serne
Keyword(s):  
Diffusion Processes ◽  
Scale Up ◽  
Liquid Waste ◽  
Effective Diffusivity ◽  
Cementitious Materials ◽  
Solidified Waste ◽  
Effective Diffusivities ◽  
Long Term Performance ◽  
Term Performance

ABSTRACTAt Hanford, low-level liquid nuclear waste is being mixed with cementitious materials (grout) to form leach-resistant solid waste. Prior to grouting each liquid waste, an assessment must be performed to evaluate the long-term environmental impact. These predictions rely upon a diffusioncontrolled release model and short-term laboratory leach data on small grout samples. This paper describes size scale-up and inventory scale-up experiments that evaluate whether diffusion does in fact control the release of contaminants. The results of the volume scale-up test suggest that tests on grout cylinders between the sizes 3 cm dia. by 3 cm length and 30 cm dia. by 29 cm length yield comparable results. These data and other available literature suggest that extrapolation of leach results to large blocks of solidified waste is defensible.The inventory scale-up tests for 125I and selenium show a constant effective diffusivity regardless of the original inventory. This suggests that diffusion processes do in fact control the release of iodide and selenium from grout. The 99Tc effective diffusivities may not remain constant with changes in inventory.

Updated Review of Stone Matrix Asphalt and Superpave® Projects

2003 ◽  
Vol 1832 (1) ◽  
pp. 217-223 ◽  
Author(s):  
Donald E. Watson
Keyword(s):  
Material Properties ◽  
The United States ◽  
Mix Design ◽  
Stone Matrix Asphalt ◽  
High Traffic Volume ◽  
Long Term Performance ◽  
Term Performance ◽  
Stone Matrix

Stone matrix asphalt (SMA) and Superpave® represent relatively new mix design technologies in the United States. Therefore, a condition survey was conducted of mixes that had been in service for several years to evaluate the long-term performance of SMA and Superpave projects. This study is a follow-up to a 1995 review of SMA projects and a 1998 review of Superpave projects. Both SMA and Superpave are acknowledged to be rut-resistant mixes, and this resistance was shown to be the case during this project review. However, a significant amount of cracking occurred early in the life of some of these mixtures. Overall, the SMA mixtures appeared to be more durable than the Superpave mixtures evaluated. The SMA mixtures have been in place about 2½ years longer than the Superpave mixtures, but the overall condition is about the same. Some of the primary conclusions from the survey are as follows: both SMA and Superpave mixtures were shown to be rut-resistant even when placed on facilities with high traffic volume; much of the observed cracking, especially load cracking, appeared to be more related to problems other than mix design or material properties; and SMA mixtures can be expected to last longer than Superpave mixtures before reaching the same condition level.

Study on the Effects of Natural Pozzolan and Limestone Powder on Mechanical Properties of Roller Compacted Concrete Pavements

2011 ◽  
Vol 250-253 ◽  
pp. 3619-3623 ◽  
Author(s):  
Morteza Madhkhan ◽  
Armin Hamidi ◽  
Navid Salehi
Keyword(s):  
Compressive Strength ◽  
Cementitious Materials ◽  
Production Costs ◽  
Limestone Powder ◽  
Concrete Pavements ◽  
Natural Pozzolan ◽  
Two Factors ◽  
Long Term Performance ◽  
Term Performance

Due to high maintenance and production costs of conventional asphalt pavements in recent years, substitution of concrete pavements has been taken into account. One important factor of such pavements is the long-term performance. The substitution of pozzolanic materials with existing cement in the mixture is a common choice to improve the durability factors and to increase the long term compressive strength. Owing to this change in cementitious materials, a general anticipation of the pozzolanic behavior to be observed is that the early age compressive strength gets decreased. On the other hand, this defect will be compensated in the long-term compressive strength. Furthermore, as conventional loads of road pavements are concerned, the tensile and flexural strengths have their own importance. Regarding these two factors, the related tests were also performed and the results were analyzed. The main purpose is to find the optimum material among these 2 types of pozzolanic supplements and its percentage of substitution with the preference of having the best average strength in both long and short term performances. Altogether, the natural pozzolan had better performance than limestone powder.

The United States Department of Energy's Environmental Management Program

2009 ◽  
Vol 1193 ◽  
Author(s):  
Kurt D. Gerdes ◽  
Steven L. Ross
Keyword(s):  
United States ◽  
Environmental Management ◽  
Risk Reduction ◽  
New Technologies ◽  
The United States ◽  
Management Program ◽  
Department Of Energy ◽  
United States Department ◽  
Environmental Benefit ◽  
Environmental Management Program

The year 2009 marks 20 years since the Environmental Management program was first established in the Department of Energy. At that time, nearly 50 years of nuclear activity had left a legacy that included nuclear waste and environmental contamination at more than 100 sites across the United States. The extent of the risk to our citizens and communities was unknown, and certainly many of the processes and technologies to reduce that risk had not yet been invented. Since then, the Department of Energy has closed 86 of 108 sites originally assigned to the program nationwide. The Department of Energy has packaged and safely stored the nation’s entire excess plutonium inventory. The Department has pioneered new technologies that have allowed progress in retrieving millions of liters of tank waste and safely disposing of tens of thousands of cubic meters of transuranic waste. In Fiscal years 2006 and 2007 alone, the Department of Energy demolished approximately 500 buildings (nuclear, radioactive, and industrial) as part of our decontamination and decommissioning projects. Finally, there have been great strides in restoring groundwater contaminated with radionuclides using innovative treatment systems. In August 2005, a rigorous project management system was instituted. This Department of Energy program was built on the principle of prioritizing risk reduction supported by our four guiding tenets of safety, performance, clean-up, and closure. The mission activities at our clean-up sites are targeted at our highest risk activities. In planning its environmental clean-up efforts and developing the budget for those activities, the Department seeks to focus on work that will produce the greatest environmental benefit and the largest amount of risk reduction.

Sign in / Sign up

Export Citation Format

Share Document