SINGLE-SHELL TANK INTEGRITY PROJECT ANALYSIS OF RECORD-PRELIMINARY MODELING PLAN FOR THERMAL AND OPERATING LOADS

This document is a Phase I deliverable for the Single-Shell Tank Analysis of Record effort. This document is not the Analysis of Record. The intent of this document is to guide the Phase II detailed modeling effort. Preliminary finite element models for each of the tank types were developed and different case studies were performed on one or more of these tank types. Case studies evaluated include thermal loading, waste level variation, the sensitivity of boundary effects (soil radial extent), excavation slope or run to rise ratio, soil stratigraphic (property and layer thickness) variation at different farm locations, and concrete material property variation and their degradation under thermal loads. The preliminary analysis document reviews and preliminary modeling analysis results are reported herein. In addition, this report provides recommendations for the next phase of the SST AOR project, SST detailed modeling. Efforts and results discussed in this report do not include seismic modeling as seismic modeling is covered by a separate report. The combined results of both static and seismic models are required to complete this effort. The SST AOR project supports the US Department of Energy's (DOE) Office of River Protection (ORP) mission for obtaining a better understanding of the structural integrity of Hanford's SSTs. The 149 SSTs, with six different geometries, have experienced a range of operating histories which would require a large number of unique analyses to fully characterize their individual structural integrity. Preliminary modeling evaluations were conducted to determine the number of analyses required for adequate bounding of each of the SST tank types in the Detailed Modeling Phase of the SST AOR Project. The preliminary modeling was conducted in conjunction with the Evaluation Criteria report, Johnson et al. (2010). Reviews of existing documents were conducted at the initial stage of preliminary modeling. These reviews guided the topics that were explored in the SST preliminary modeling. The reviews determined the level of detail necessary to perform the analyses of the SSTs. To guide the Phase II detailed modeling effort, preliminary finite element models for each of the tank types were developed and different case studies were performed on one or more of these tank types. Case studies evaluated include thermal loading, waste level variation, the sensitivity of boundary effects (soil radial extent), excavation slope or run to rise ratio, soil stratigraphic (property and layer thickness) variation at different farm locations, and concrete material property variation and their degradation under thermal loads. Conclusions were derived from case studies on one of the tank types when no additional runs of similar cases on other types of tanks were found necessary to derive those conclusions. The document reviews provided relatively complete temperature histories for Type IV tanks. The temperature history data for Type I, II, and III tanks was almost nonexistent for years prior to 1975. Document reviews indicate that there might be additional useful data in the US Department of Energy, Richland Operations Office (DOE-RL) records in Seattle, WA, and these records need to be reviewed to extract data that might have been disregarded during previous reviews. Thermal stress analyses were conducted using different temperature distribution scenarios on Type IV tanks. Such studies could not be carried out for other tank types due to lack of temperature history data. The results from Type IV tank analyses indicate that factors such as temperature distribution in the tank waste and rate of rise in waste temperature have a significant impact on the thermal stresses in the tank structures. Overall, the conclusion that can drawn from the thermal stress analyses is that these studies should be carried out for all tank types during the detailed analysis phase with temperature values that are reasonably close to the typical temperature histories of the respective tank types. If and/or when additional waste temperature data is acquired for tank Type I, II, and III tanks, additional cases need to be considered as tank structural integrity is sensitive to thermal loads. A few case studies were also performed using Type IV-b models to comprehend the effects of excavation boundaries, change in soil stratigraphy (layer thickness and properties), and radial extent of soil in the finite element models. The result from the case studies indicates that the slight variation in soil stratigraphy has little effects on the tank sections force and moment demands under mechanical loads. The case study for excavation slope or backfill transition boundary indicated that inclusion of such boundary yields conservative demands in the wall region while demands at other locations remain unaffected. Hence this excavation slope will be modeled in the detailed analysis of SSTs

Gold nanoparticles: New routes across old boundaries

In recent years, gold nanoparticles have emerged as unique non-invasive drug carriers for targeting drugs to their site of action. Their site specificity has helped in increasing drugs’ efficacy at lower dose as well as reduction in their side effects. Moreover, their excellent optical properties and small size offer their utilization as diagnostic tools to diagnose tumors as well as other diseases. This review focuses on various approaches that have been used in last several years for preparation of gold nanoparticles, their characterization techniques and theranostic applications. Their toxicity related aspects are also highlighted. Gold nanoparticles are useful as theranostic agents, owing to their small size, biocompatible nature, size dependent physical, chemical and optical properties etc. However, the challenges associated with these nanoparticles such as scale up, cost, low drug payload, toxicity and stability have been the major impediments in their commercialization. The review looks into all these critical issues and identifies the possibilities to overcome these challenges for successful positioning of metallic nanoparticles in market

Methanogens, sulphate and heavy metals: a complex system

Anaerobic digestion (AD) is a well-established technology used for the treatment of wastes and wastewaters with high organic content. During AD organic matter is converted stepwise to methane-containing biogasa renewable energy carrier. Methane production occurs in the last AD step and relies on methanogens, which are rather sensitive to some contaminants commonly found in wastewaters (e.g. heavy metals), or easily outcompeted by other groups of microorganisms (e.g. sulphate reducing bacteria, SRB). This review gives an overview of previous research and pilot-scale studies that shed some light on the effects of sulphate and heavy metals on methanogenesis. Despite the numerous studies on this subject, comparison is not always possible due to differences in the experimental conditions used and parameters explained. An overview of the possible benefits of methanogens and SRB co-habitation is also covered. Small amounts of sulphide produced by SRB can precipitate with metals, neutralising the negative effects of sulphide accumulation and free heavy metals on methanogenesis. Knowledge on how to untangle and balance sulphate reduction and methanogenesis is crucial to take advantage of the potential for the utilisation of biogenic sulphide as a metal detoxification agent with minimal loss in methane production in anaerobic digesters.The research was financially supported by the People Program (Marie Curie Actions) of the European Union's Seventh Framework Programme FP7/2007-2013 under REA agreement 289193

New Scan-Based Attack Using Only the Test Mode and an Input Corruption Countermeasure

International audienceScan-based design-for-testability, which improves access and thus the test quality, is highly vulnerable to scan attack. While in-field test is enabled through the scan design to provide debug capabilities, an attacker can leverage the test mode to leak the secret key of the chip. The scan attack can be thwarted by a simple defense that resets the data upon a switch from the normal mode to the test mode. We proposed a new class of scan attack in [15] using only the test mode of a chip, circumventing this defense. In this book chapter we extend our earlier work by introducing case studies to explain this new attack in greater detail. Furthermore, we study the effectiveness of existing countermeasures to thwart the attack and propose a new input corruption countermeasure that requires a smaller area overhead compared to the existing countermeasures

SINGLE-SHELL TANK INTEGRITY PROJECT ANALYSIS OF RECORD-PRELIMINARY MODELING PLAN FOR THERMAL AND OPERATING LOADS

This document is a Phase I deliverable for the Single-Shell Tank Analysis of Record effort. This document is not the Analysis of Record. The intent of this document is to guide the Phase II detailed modeling effort. Preliminary finite element models for each of the tank types were developed and different case studies were performed on one or more of these tank types. Case studies evaluated include thermal loading, waste level variation, the sensitivity of boundary effects (soil radial extent), excavation slope or run to rise ratio, soil stratigraphic (property and layer thickness) variation at different farm locations, and concrete material property variation and their degradation under thermal loads. The preliminary analysis document reviews and preliminary modeling analysis results are reported herein. In addition, this report provides recommendations for the next phase of the SST AOR project, SST detailed modeling. Efforts and results discussed in this report do not include seismic modeling as seismic modeling is covered by a separate report. The combined results of both static and seismic models are required to complete this effort. The SST AOR project supports the US Department of Energy's (DOE) Office of River Protection (ORP) mission for obtaining a better understanding of the structural integrity of Hanford's SSTs. The 149 SSTs, with six different geometries, have experienced a range of operating histories which would require a large number of unique analyses to fully characterize their individual structural integrity. Preliminary modeling evaluations were conducted to determine the number of analyses required for adequate bounding of each of the SST tank types in the Detailed Modeling Phase of the SST AOR Project. The preliminary modeling was conducted in conjunction with the Evaluation Criteria report, Johnson et al. (2010). Reviews of existing documents were conducted at the initial stage of preliminary modeling. These reviews guided the topics that were explored in the SST preliminary modeling. The reviews determined the level of detail necessary to perform the analyses of the SSTs. To guide the Phase II detailed modeling effort, preliminary finite element models for each of the tank types were developed and different case studies were performed on one or more of these tank types. Case studies evaluated include thermal loading, waste level variation, the sensitivity of boundary effects (soil radial extent), excavation slope or run to rise ratio, soil stratigraphic (property and layer thickness) variation at different farm locations, and concrete material property variation and their degradation under thermal loads. Conclusions were derived from case studies on one of the tank types when no additional runs of similar cases on other types of tanks were found necessary to derive those conclusions. The document reviews provided relatively complete temperature histories for Type IV tanks. The temperature history data for Type I, II, and III tanks was almost nonexistent for years prior to 1975. Document reviews indicate that there might be additional useful data in the US Department of Energy, Richland Operations Office (DOE-RL) records in Seattle, WA, and these records need to be reviewed to extract data that might have been disregarded during previous reviews. Thermal stress analyses were conducted using different temperature distribution scenarios on Type IV tanks. Such studies could not be carried out for other tank types due to lack of temperature history data. The results from Type IV tank analyses indicate that factors such as temperature distribution in the tank waste and rate of rise in waste temperature have a significant impact on the thermal stresses in the tank structures. Overall, the conclusion that can drawn from the thermal stress analyses is that these studies should be carried out for all tank types during the detailed analysis phase with temperature values that are reasonably close to the typical temperature histories of the respective tank types. If and/or when additional waste temperature data is acquired for tank Type I, II, and III tanks, additional cases need to be considered as tank structural integrity is sensitive to thermal loads. A few case studies were also performed using Type IV-b models to comprehend the effects of excavation boundaries, change in soil stratigraphy (layer thickness and properties), and radial extent of soil in the finite element models. The result from the case studies indicates that the slight variation in soil stratigraphy has little effects on the tank sections force and moment demands under mechanical loads. The case study for excavation slope or backfill transition boundary indicated that inclusion of such boundary yields conservative demands in the wall region while demands at other locations remain unaffected. Hence this excavation slope will be modeled in the detailed analysis of SSTs

Exploring role of polysaccharides present in Ganoderma lucidium extract powder and probiotics as solid carriers in development of liquisolid formulation loaded with quercetin: A novel study.

Ganoderma lucidium extract powder (GLEP) contains various polysaccharides which are well known for their antioxidant and anti-inflammatory actions. Probiotics (PB) are well-established for providing a plethora of health benefits. Hence, use of mushroom polysaccharides and probiotics as carriers to solidify liquisolid formulation is anticipated to function as functional excipients i.e. as adsorbent that may provide therapeutic benefits. Quercetin (QUR) has been used as model lipophilic drug in this study. QUR loaded liquisolid compacts (LSCs) were formulated using Tween 80 as solvent. These were further solidified using a combination of PB and GLEP as carriers. Aerosil-200 (A-200) was used as coating agent. The formulation exhibited very good flow characteristics. Dissolution rate of raw QUR was found to be less than 10% in 60 min while in case of QUR loaded LSCs, more than 90% drug release was observed within 5 min. Absence of crystalline peaks of QUR in the DSC and PXRD reports of LSCs and their porous appearance in SEM micrographs indicate that QUR was successfully incorporated in the LSCs. The developed formulation was found to be stable on storage under accelerated stability conditions