bluuebunny/crossref_metadata_2025 huggingface dataset:
Field Performance of Single-Ply, Chlorinated Polyethylene (CPE) Roof Membranes
Authors: French WR
Published: March 2009

This paper will present the results of a field study of 29 different recover roofing systems installed on a variety of buildings. All of the buildings were located in Southeast Texas and were exposed to a variety of conditions related to use, coastal environment and drainage characteristics. Installation methods included mechanically fastened and fully-adhered (fleece-backed) membranes. Substrates included a number of different deck types and original membrane types, as well as various recover insulation materials, including glass fiber, perlite, wood fiber and expanded polystyrene (EPS). A number of these roofs exhibited areas of chronic and long-term ponded water. An intensive visual study was made regarding the effect of ponding on the CPE roof systems and the deterioration occurring in those locations. Laboratory testing on a number of the roofs revealed aging effects on some membrane physical properties. A number of other performance characteristics are assessed and general observations presented, including detailing practices and conformance with industry standards.
Comprehensive Research Program: Wind Resistance of Asphalt Shingles
Authors: Jones JE , Metz RE
Published: March 2009

This paper describes the Asphalt Roofing Manufacturers Association's comprehensive research program which has resulted in a validated wind load model that can be used to calculate the uplift pressure on asphalt shingles as a function of approach wind velocities and other wind and building conditions. Also, a tab uplift resistance test method has been developed to measure the ability of asphalt shingles to withstand the imposed pressures due to the wind. In combination, the results of these two efforts provide the shingle manufacturers with the methodology to evaluate and improve their products. The results are not only of interest to the roofing manufacturers, but also to contractors, code officials, insurance companies, roofing specifiers and other professionals in the roofing industry. The results of this work should provide building owners and homeowners with high performance asphalt shingles for extreme wind conditions.
On the Study of Crack-Initiation Fracture Toughness of Fiber Glass Asphalt Shingles
Authors: Shiao ML
Published: March 2009

The fracture behavior of fiber glass asphalt shingles was examined by measuring their J-integral fracture toughness at crack initiation. The corresponding fracture mechanisms were also studied by in situ fracture observation and by scanning electron microscopy. The applicability of using J-integral fracture toughness to characterize asphalt shingles was discussed and its relationships to other mechanical properties was established. The results indicated that the fracture toughness at crack initiation can be accurately measured for fiber glass shingles and the values may be used to characterize their cracking resistance. Fracture toughness measured from various shingle samples was found to correlate to the shingle's tensile toughness and to its tear strength. Preliminary results on fracture mechanisms suggested that failure in the asphalt coatings by micro-cavitation may be the controlling event leading to crack advance. The importance of the glass fiber mat on a shingle's resistance to fracture was also discussed.
Laboratory Evaluation of Mechanical Properties of Rock Using an Automated Triaxial Compression Test with a Constant Mean Stress Criterion
Authors: Mellegard KD , Pfeifle TW
Published: March 2009

A computerized, servohydraulic test system has been used in the laboratory to perform axisymmetric, triaxial compression tests on natural rock salt using a load path that maintains constant mean stress. The constant mean stress test protocol illustrates that modern test systems allow a nonstandard load path which can focus on a particular aspect of rock characterization; namely, the onset of dilation. Included are discussions of how the constant mean stress test could be used to investigate material anisotropy and determine elastic moduli. The results from the constant mean stress tests are compared to test results from a traditional test method used to investigate dilation of rock salt. The comparison verifies that the constant mean stress protocol may be preferable to the more traditional test method. The paper also addresses system calibration concerns and the effects of pressure changes on the direct-contact extensometers used to measure strain.
Effects of Product Quality and Design Criteria on Structural Integrity
Authors: Rice RC , Tritsch DE
Published: March 2009

Description

Explores ways to increase the reliability in the initial quality of engineering materials, components and structures.

Leading experts in the field have presented eleven peer-reviewed papers addressing such issues as:

• The impact of production processing changes on laminated high-strength stainless steel corrosion damage and fatigue strength loss

• High temperature applications using fracture mechanics methodologies

• The influence of density and porosity size and shape on the fatigue properties of a high-strength powder metallurgy steel

• How to alleviate performance problems in a nickel base fastener system

• The effect of alterations in plating and shot peening design criteria on 4340 steel plate fatigue properties

• Fatigue behavior alteration in scale-model reinforced concrete bridge decks subjected to moving loads

• Design criteria and analysis procedures for reliable commercial transport aircraft maintenance

• Design methods to address crack arrest and avoid brittle failure in low-temperature storage tanks.
Advances in Fatigue Crack Closure Measurement and Analysis: Second Volume
Authors: McClung RC , Newman JC
Published: March 2009

Description

STP 1343 features 28 peer-reviewed papers addressing development in fatigue crack growth (FTG) and fatigue life management. Worldwide leaders in the field provide their latest findings in five major areas:

Fundamental Studies -- answers basic questions about plasticity-induced crack closure and the adequacy of closure concepts in a wide range of growth behaviors.

Experimental Characterization of Closure -- examines one of the most active topics in closure studies. Included are experimental methods of measuring and analyzing crack opening levels and the correct way to incorporate closure information into the effective value of the stress intensity factor range.

Load History Effects -- addresses perhaps the most useful application of the crack closure concept, which has been to develop life prediction methods accounting for retardation and acceleration effects under variable-amplitude and spectrum loading methods.

Surface Roughness Effects -- explores how roughness interacts with plasticity-induced closure to affect crack growth rates. Several authors address this issue by developing models that include both effects.

Closure Effects on Crack Behavior -- investigates how fatigue crack closure, as an intrinsic feature of growing fatigue cracks, can have an influence on many different aspects of crack growth.

Organized according to the particular class of closure and including a variety of both experimental and analytical/numerical techniques, STP 1343 is an invaluable resource for all FTG experts.
Applications of Inductively Coupled Plasma-Mass Spectrometry to Radionuclide Determinations
Authors: Morrow RW , Crain JS
Published: March 2009

Description

Features the most current methods for determining precise levels of radiation exposure using state-of-the-art instrumentation. An international selection of experts in the field from the United States, Europe and the Middle East have presented 13 comprehensive, peer-reviewed papers in two key categories:

Applications of ICP-MS in the Nuclear Fuel Cycle -- Topics covered include ICP-MS use for isotopic composition assessment in uranium products; refinements for the precise determination of uranium isotope ratios; on-site applications ranging from environmental monitoring to defense waste vitrification; and ICP-MS applications toward nuclear waste management in France.

Applications of ICP-MS in Health and Environmental Monitoring -- Key issues examined: On-line sample processing techniques for the determination of actinides in natural waters; Radionuclides determination in clinical media; and ICP-MS methods for the characterization of geological media.

This publication is an invaluable text for analytical spectroscopists, radiochemists, nuclear fuel fabricators, geochemists, environmental restoration companies and Department of Energy contractors.
Pesticide Formulations and Application Systems: Eighteenth Volume
Authors: Nalewaja JD , Goss GR , Tann RS
Published: March 2009

Description

Pesticide Formulations and Application Systems: 18th Volume (STP 1347) provides 26 peer-reviewed papers from application, formulation, and synthesis professionals from academia, government, and industry. The volume is divided into three areas:

Current Issues -- the impact of pesticide and insect resistant crops on pesticide and adjuvant usage and regulatory concerns; the advantages and disadvantages of transgenic crops and potential shifts in pesticide usage; basic principles of endocrine disruption, compounds considered disrupters; the activities of the Endocrine Disrupter Screening and Testing Advisory Committee that was established to help the EPA with guidelines for the Congressional set date of August 1999.

Application Technology -- Innovations in pesticide spray applications; influence of species, spray volume, droplet size, adjuvant type and amount of spray retained; closed systems for spray application; spray distribution patterns; mechanism of spray droplet wetting and spreading; and surface tension affects on droplet spectrum.

Pesticide Formulations and Adjuvants -- Various components for liquid, flowable, and granular pesticide formulations are discussed in several papers. The surface acidity of clay carriers relative to pesticide stability, the use of computer models for developing emusifiable formulations; rapid tests for adjuvant efficacy with specific herbicides; and the blends of dispersing agents and surfactants for suspension stability are specific topics addressed.

Topics relating to adjuvant enhanced efficacy are adjuvant physicochemical properties; surfactant phytotoxicity to plants and cell suspensions; spray droplet retention and spread relative to efficacy with herbicides; potential of corn syrup as an adjuvant; and methods of evaluating adjuvant efficacy.

For pesticide formulators, pesticide developers, agricultural consultants, weed, insect, and plant disease scientists. Also for general formulation chemists (as in the paint industry, pharmaceuticals, inks, etc.) and pesticide distributors.
Acoustic Emission: Standards and Technology Update
Authors: Vahaviolos SJ
Published: March 2009

Description

This comprehensive volume presents 16 peer-reviewed papers that explore the evolution of AE technology worldwide and provide you with the latest information on AE instrumentation, applications, standards and codes. STP 1353 also draws comparisons between AE and other Nondestructive Testing (NDT) technologies are examined as to their suitability in solving practical industrial problems; and covers Natural Gas Vehicle (NGV) Cylinder Testing with AE, which when properly applied, can save NGV assets.

This unique publication is a valuable asset to:

• Professionals at Petrochemical Plants and Refineries

• Power Generation and Distribution Industry Personnel

• Bridge Inspectors

• Railroad Tank Car Users and Leasers

• Compressed Natural Gas Users and Component Manufacturers

• NDT Community

• Researchers

• University Professors and Students
Field Instrumentation for Soil and Rock
Authors: Durham GN , Marr WA
Published: March 2009

Description

Nearly 30 papers feature the latest information on field instrumentation for soil and rock

Three major areas addressed include: • Geotechnical Instrumentation of Landfills; • Instrumentation for Project Cost Management, • and Field Data Acquisitions and Data Management.

Two papers address the geotechnical instrumentation aspects of the Central Artery/Tunnel Project in Boston, Massachusetts, while other papers address topics such as, culverts and buried pipe, instrumenting corrugated pipe, instrumentation of geogrid used in a reinforced slope, geotechnical instrumentation of landfills and more.
Materials Selection: Multiple Constraints and Compound Objectives
Authors: Ashby MF
Published: March 2009

Systematic procedures for selecting candidate materials for an engineering component now exist. One class of these makes use of material indices and limits, which, when plotted on material-property charts, identify a subset of materials that optimally meet a given design specification. The procedure is straightforward when the design of the component specifies a simple objective (such as minimizing weight) and a single constraint (a specified stiffness, strength, or thermal conductance, for instance). But real components almost always must meet several conflicting constraints, and objectives are seldom simple and require compromise. This paper develops ways of dealing with multiple constraints and compound objectives within the framework of the material-index and property-chart method.
The use of Thermal Analysis to Assess Oxidative Damage in Polyolefins
Authors: Horrocks AR , Mwila J , Liu M
Published: March 2009

During the thermal oxidation of polyolefins, exemplified by isotactic polypropylene, few observable physical and chemical changes occur until embrittlement or similar failure. The increasing oxidative and auto-oxidative behavior that accompanies oxidation can be measured as a reducing oxidation induction time using isothermal thermal analysis. Alternatively, dynamic thermal analysis (DSC or TGA) may be used more conveniently to record the shift to lower temperatures of the post-fusion, oxidative exotherm quantified as an onset (Ton) temperature. This paper collates data from a number of previous and current studies on the oxidative behavior of oriented polypropylene tapes and filaments exposed at elevated (130°C) temperature in air. During exposure, Ton values decrease according to a power law dependence with time and these shifts may be used to assess degrees of oxidation present in aged specimens. The implications of these shifts are discussed in tenns of monitoring in-service behavior of exposed polyolefins and their relationship to oxidative and auto-oxidative mechanisms are discussed.
An Assessment of Potential Gamma Ray Enhancement of Embrittlement in ABWR Pressure Vessel Walls
Authors: Garner FA , Greenwood LR , Roy P
Published: March 2009

It has recently been proposed that the unequal attenuation of γ-rays and fast neutrons in the water gaps of boiling water reactors may lead to a significant underprediction of the atomic displacement rate at the pressure vessel wall. Since a larger water gap has been incorporated in the design of the Advanced Boiling Water Reactor (ABWR), it was suggested that atomic displacements by γ-rays might significantly offset the advantage of reduced neutron damage to the wall gained by using the larger gap. Such a proposal is strongly amplified by another proposed assumption that atomic displacements generated by γ-rays are 100 times more survivable and therefore more damaging than those created by fast neutrons.

An independent assessment of the relative displacements caused by γ-rays and neutrons in the ABWR pressure vessel wall has been performed in this study. Based on recent works of others it does not appear that the use of 100-fold enhancement factors is justified for this application. When the full details of the neutron and gamma transport are addressed, it is found that no significant γ-enhancement of damage will occur in the ABWR pressure vessel wall. While the relative amount of damage caused by neutrons and gammas changes with increasing water gap, the overall advantage of low total displacement damage is not significantly changed by the gamma-induced component.
Comparison of Irradiation-Induced Shifts of KJc and Charpy Impact Toughness for Reactor Pressure Vessel Steels
Authors: Sokolov MA , Nanstad RK
Published: March 2009

The current provisions for determination of the upward temperature shift of the lower-bound static fracture toughness curve due to irradiation of reactor pressure vessel steels are based on the assumption that they are the same as the Charpy 41-J shifts as a consequence of irradiation. The objective of this paper is to evaluate this assumption relative to data reported in open publications. Depending on the specific source, different sizes of fracture toughness specimens, procedures of the KJc determination, and fitting functions were used. It was anticipated that the scatter might be reduced by using a consistent approach to analyze the published data. A method employing Weibull statistics is applied to analyze original fracture toughness data of unirradiated and irradiated pressure vessel steels. Application of the master curve concept is used to determine shifts of fracture toughness transition curves. A hyperbolic tangent function is used to fit Charpy absorbed energy data. The fracture toughness shifts are compared to Charpy impact shifts evaluated with various criteria. Linear regression analysis showed that for weld metals, on average, the fracture toughness shift is the same as the Charpy 41-J temperature shift, while for base metals, on average, the fracture toughness shift at 41 J is 16% greater than the shift of the Charpy 41-J transition temperature, with both correlations having relatively large 95% confidence intervals.
Behavior of an Oxide Dispersion Strengthened Ferritic Steel Irradiated in Phenix
Authors: Dubuisson P , Schill R , Hugon M-P , Grislin I , Séran J-L
Published: March 2009

This paper deals with the irradiation behavior of the oxide dispersion strengthened (ODS) ferritic alloy DT2203Y05, a 13% Cr ferritic alloy strengthened by a fine dispersion of yttrium and titanium oxides. This alloy was irradiated up to 81 dpa in Phénix as fuel pin cladding. The profilometry measurements confirm its high swelling resistance. Few voids, mainly associated with oxides, are observed at low irradiation temperatures, but this alloy is severely embrittled by irradiation. A few cracks are observed in the lower 2/3 of the fissile column, and the longitudinal tensile tests show hardening and severe ductility loss induced by irradiation along the whole fuel column.

Transmission electron microscopy observations show that the radiation-induced strong ductility loss results from a fine and uniform α′ precipitation and dislocation loop formation at low temperatures (as in classic ferritic steels) and from important χ precipitation at high temperatures. The radiation-induced embrittlement of this ODS ferritic steel results also from the recoil dissolution of oxides leading to the total dissolution of the finer oxides and to the formation of small oxide shells around the larger initial oxides. The oxide dispersion, which is characterized before irradiation by a broad size distribution with oxide-free bands leading to an heterogeneous dislocation loop distribution under irradiation, is probably responsible for the apparition of cracks in the lower 2/3 of the fuel column and for the channel fracture.
Brazed Dispersion Strengthened Copper: The Effect of Neutron Irradiation and Transmutation on Bond Integrity
Authors: Edwards DJ , Hamilton ML , Garner FA , Samal P , Troxell JD
Published: March 2009

Four types of brazes were used to join sheets of GLIDCOP™ Al25. Miniature tensile specimens were fabricated from the joints and irradiated under various conditions for a study of their response to high temperature neutron irradiation in FFTF Two of the sets of specimens, brazed with TiCuAg and TiCuNi, were found to possess low quality joints because of excessive diffusion of silver into the base metal in the case of the TiCuAg, and melting of the base metal in the case of the TiCuNi. Joints produced with a CuAu braze were satisfactory for the unirradiated state, but transmutation of Au to Hg affected the integrity of the joints irradiated in a below-core position where the transmutation rate per dpa was rather high. A CuAg braze yielded satisfactory joints in the unirradiated state and held up well when the irradiated specimens were tested. However, transmutation of Ag to Cd leads to a high residual radioactivity that may limit the usefulness of this braze after exposure to neutron irradiation.
Comfort or Protection: The Clothing Dilemma
Authors: Slater K
Published: March 2009

The need to provide protection from a variety of hazards is often met by the use of special clothing. Unfortunately, complete protection often necessitates apparel design which, for various reasons, cannot be tolerated by the human body.

The dilemma relates to human comfort and survival needs. People cannot tolerate lack of oxygen, nor can they survive exposure to excess heat, occasioned by preventing moisture resulting from perspiration from escaping into the atmosphere. Lack of air, or water build-up inside a garment can literally produce serious physiological overloading, ending possibly in death if the situation is not corrected. Thus, for instance, although protection from chemical, microbiological or radiative harm can theoretically be provided by total isolation of the body within a garment system, this approach is not feasible in practice, both because of breathing difficulties and because of heat build-up.

In this paper, the conflicting factors involved in providing protection while maintaining comfort are reviewed, and the current solutions proposed for resolving the dilemma, including the use of coated or microporous fabrics, external cooling or air supply arrangements, and clothing design, are critically evaluated.
The Effect of Nomex®/Kevlar® Fiber Blend Ratio and Fabric Height on Fabric Performance in Static and Dynamic TPP Tests
Authors: Barker RL , Geshury AJ , Behnke WP
Published: March 2009

This research provides an understanding of how the weight of Nomex® and Kevlar® fiber blend compositions determine performance of a selected group of single-layer aramid protective fabrics in static and dynamic TPP tests. It demonstrates that material factors controlling fabric barrier and insulative performance are fundamentally different: aramid fabric weight determines the comparative protective performance of these materials in a static TPP test that uses an air gap between the fabric specimen and heat sensor to measure barrier protection. In this test, greater fabric weight slows the rate of fabric heating, prolonging the time required for the fabric to become a significant reradiator of thermal energy. By comparison, heat transfer in a dynamic TPP test used in this study occurs, not only by backside radiation, but by conductive transmission occurring whenever the fabric contacts the instrumented thermal sensor. Thermal transfer can also take place as a result of catastrophic break-open of the test specimen inducted by the mechanical restraints and flexing action of the dynamic tester. In either case, the thermal stability of the aramid fabric material, determined by its strength retention in flames or resistance to heat shrinkage, emerges as a crucial factor determining protective insulation. This research advances a quantitative model for predicting the heat shrinkage of aramid fabrics based on the blend ratio of Kevlar® and Nomex® fibers. This model effectively explains the performance of aramid fabrics in a dynamic TPP test. It explains the role of Kevlar® fibers in stabilizing a Nomex® blend against heat shrinkage and suggests a minimum concentration of Kevlar® to optimize fabric performance in dynamic TPP exposures.
The Design of a Surface Heat Flux Transducer for Use in Fabric Thermal Protection Testing
Authors: Grimes R , Mulligan JC , Hamouda H , Barker R , Soroka AJ
Published: March 2009

From theoretical considerations, a custom slug calorimeter heat flux transducer was developed for experimental use in the measurement of heat fluxes transferred through layers of fabric to the surface of a human mannequin during simulated flash fire conditions. This paper describes the determination of the transducer's physical size, its limitations and heat loss considerations, a computer simulation of transducer operation and the evaluation of transient heat flux measurements. The transducer's loss factors were predicted numerically and determined experimentally. The overall performance of the transducer was also examined under varying simulated applied heat flux input.
Basic Considerations in the Application of Vitrification Technologies
Authors: Pegg IL
Published: March 2009

The application of vitrification technology to hazardous, radioactive, and mixed-waste treatment problems is discussed in terms of the requirement to satisfy a variety of constraints imposed on glass formulation development and process design or selection. The major classes of vitrification technologies are briefly described and waste stream characterization requirements are discussed. Each of the key constraints on glass formulation development - economics, processability, and product performance - are broken down into the principal factors that determine these qualities. Factors affecting the selection of appropriate processes and process operating conditions for a particular waste treatment problem are discussed. Particular attention is paid to processing temperature selection with respect to off-gas and waste loading trade-offs. A simple model showing the benefits of off-gas recycle for problems involving volatile inorganic contaminants is described.
Mechanisms of Metal Containment Resulting from the Solidification of a Commercially Produced Stabilized Waste
Authors: Cheeseman CR , Sollars CJ , Perry R
Published: March 2009

The stabilized filter cake produced at a commercial stabilization/solidification plant, which treats a wide variety of inorganic solid wastes and effluents, has been characterized, and subsequently solidified by adding increasing amounts of cement and fly ash. This stabilized waste interacts with the cementitious additives so that the normal products of hydration are no longer produced. A solidified material is, however, still formed, and ettringite is the main crytalline product. The degree of chemical containment has been determined by completing single extraction batch leach tests under increasingly aggressive conditions. Results indicate that hazardous heavy metals are well retained by the solidified wastes, while they are readily leached from the stabilized filter cake. The concentrations of metals released from the stabilized waste and the solidified materials exhibit the same behaviour as a function of leachate pH. This demonstrates that a major effect of the cementitious additives is to change the composition of the leaching fluid. The addition of solidified wastes containing increasing amounts of cementitious additives to an acidic leachant causes Ca2+ to leach at a concentration determined by the acidity of the leachant. Mixes containing low additions of cementitious additives cannot release sufficient Ca2+, the leachate remains acidic, and heavy metals present in the waste are able to leach.
Microbially Influenced Degradation of Cement-Solidified Low-Level Radioactive Waste Forms
Authors: Rogers RD , Hamilton MA , Veeh RH , McConnell JW
Published: March 2009

Because of its apparent structural integrity, cement has been widely used in the United States as a binder to solidify Class B and C low-level radioactive waste (LLW). However, the resulting cement preparations are susceptible to failure due to the actions of stress and environment. This paper contains information on three groups of microorganisms that are associated with the degradation of cement materials : sulfur-oxidizing bacteria (Thiobacillus), nitrifying bacteria (Nitrosomonas and Nitrobacter), and heterotrophic bacteria, which produce organic acids. Preliminary work using laboratory- and vendor-manufactured, simulated waste forms exposed to thiobacilli has shown that microbiologically influenced degradation has the potential to severely compromise the structural integrity of ion-exchange resin and evaporator-bottoms waste that is solidified with cement. In addition, it was found that a significant percentage of calcium was leached from the treated waste forms. Also, the surface pH of the treated specimens was decreased to below 2. These conditions apparently contributed to the physical deterioration of simulated waste forms after 30 to 60 days of exposure.
Preliminary Tests of an Infrared Process Monitor for Polyethylene Encapsulation of Radioactive Waste
Authors: Wright SL , Jones RW , McClelland JF , Kalb PD
Published: March 2009

Polyethylene encapsulation is a process that is being nvestigated for the solidification of radioactive nitrate salts at Brookhaven National Laboratory and Rocky Flats Plant. In the encapsulation process, radioactive-salt waste is mixed with polyethylene pellets, heated, and extruded as a molten stream. Upon cooling, the mixture solidifies to a monolithic waste form with excellent properties for long-term waste storage. This paper describes a novel method to monitor the composition of the salt/polymer stream as it exits the extruder.

The monitor is based on a technique known as transient infrared spectroscopy (TIRS). The TIRS monitor is able to capture the real-time mid-infrared spectrum of the processed waste stream as it exits the extruder. The wealth of chemical information contained in a mid-infrared spectrum makes this technique very appealing for on-line monitoring and process control. Data from the monitor can be used to guide processing, minimize waste volume, and certify the composition of the final waste form.
Summary of U.S. EPA Research on Solidified/stabilized Waste Form Long-Term Durability
Authors: Kirk DR
Published: March 2009

Successful performance of solidification and stabilization treatment technologies largely depends on the ability of the treated waste to endure long term exposure to physical and chemical stresses. The available test methods to assess durability of treated wastes rely on results from laboratory tests; these procedures rely on freeze/thaw cycles, elevated temperature, and exposure to various solutions to simulate the stresses exerted on a solidified/ stabilized (S/S) waste form over time. Unfortunately, none of the methods has been verified as replicating field behavior. In addition, the speciation of contaminants is a critical factor in determining long-term immobilization. Research is needed to cover areas which will address the issues associated with long-term performance of S/S waste forms. This paper discusses technical issues associated with long-term behavior of S/S waste forms and U.S. EPA research addressing these issues.
Leaching Behavior of Polyethylene Encapsulated Nitrate Waste
Authors: Fuhrmann M , Kalb PD
Published: March 2009

The leaching behavior of sodium nitrate salts (simulating wastes from the Hanford single-shell tanks) encapsulated in polyethylene was investigated. These wastes are sufficiently radioactive that they may be self-heating. Laboratory scale waste forms prepared for leach tests were mixtures of NaNO3 and low-density polyethylene, with nominal salt loadings of 50, 60 and 70 wt%. In this study we determined: (1) leach rates of NaNO3/polyethylene waste forms at several waste loadings (2) leach rates at temperatures as high as 70°C which is the maximum projected temperature of this self-heating waste (3) leaching mechanism of NaNO3/polyethylene waste forms and predicted releases.

The Accelerated Leach Test (ALT) used for this study was recently developed at Brookhaven National Laboratory (BNL). It is particularly well suited for this application since it was designed to be run at elevated temperatures.
Stabilization/Solidification (S/S) of Heavy Metal Contaminated Soils by Means of a Quicklime-Based Treatment Approach
Authors: Dermatas D , Meng X
Published: March 2009

The effectiveness of a quicklime-based treatment on reducing the mobility of heavy metals (lead, chromium, arsenic and mercury) in contaminated soils was evaluated using both slurry batch-contact and optimum water content compaction experimental techniques. The results indicated that lead, arsenic and trivalent chromium leachabilities were significantly reduced as a result of the quicklime treatment, while at the same time significant strength gains were evidenced for the treated soils. However, more hexavalent chromium was released from lime treated mixes than from the untreated solid due to the low adsorption and high solubility of chromate at high pHs. The results obtained from pH-controlled extraction, x-ray diffraction and scanning electron microscopy suggested that a significant portion of the immobilized heavy metals are strongly associated with pozzolanic reaction products.
Use of the Shrinking Core / Exposure Model to Describe the Leachability from Cement Stabilized Wastes
Authors: Hinsenveld M , Bishop PL
Published: March 2009

Based on physical evidence and observation of the acid dependency of the leaching process, a shrinking core model seems to be an appropriate model for cement stabilized waste. It is argued that for cement stabilized wastes, the bulk diffusion model is likely to be in error. Recent findings will be used to support the concept of a shrinking core model.

To be able to deal with varying acidities in the leachant, the concept of exposure will be introduced. The model will be derived for a flat surface to illustrate that, as in the ANS 16.1 model, a parabolic leaching behavior can be obtained. Some other characteristics of the model are indicated.

It is shown that the shrinking core model, using the concept of exposure, adequately takes into account the physical observations as well as adequately correlates the leaching data for a model specimen contaminated with lead. The findings indicate that kinetic factors may play a role in the release of metals. Their relevance for the interpretation of TCLP results is indicated.
Volatilization Modeling of Semivolatile Organic Compounds During Solidification Processes
Authors: Sass BM , Smith LA , Huang WMC , Rosansky SH , Drescher E
Published: March 2009

Technical information is provided on the effects of temperature elevation on increasing the volatility of semivolatile organic compounds (SVOCs) in stabilization media. A chemical diffusion model was developed (1) to establish a technical basis for determining maximum treatment temperatures above which SVOCs should not be exposed during solidification processes to reduce the potential for unacceptable releases; and (2) to prescribe types of binders with sufficiently low heat output to stabilize organics that have potential for volatilizing with moderate heating, and to recommend against use of others that may not maintain the mixture at sufficiently low temperatures. A non-steady-state model for linear diffusion in the aqueous and vapor phases was used because the SVOC dynamics of diffusion are controlled by resistances in both pore water and air. The results of volatilization calculations performed are presented.
In Situ Solidification/Stabilization Pilot Study for the Treatment of Coal Tar Contaminated Soils and River Sediments
Authors: Lawson MA , Venn JG , Pugh LB , Vallis T
Published: March 2009

Coal tar contamination was encountered at a former coal gasification site in soils below the groundwater table, and in the sediments of the adjacent river. Ex situ remediation techniques at this site would be costly because of the need to dewater the impacted media. In situ solidification/stabilization was tested to evaluate its effectiveness. Treatability testing was performed to evaluate a Portland cement/fly ash binder system with added stabilizing agents. Results were sufficiently promising to warrant pilot testing.

Grout containing Portland cement, fly ash, organically modified clay, and granular activated carbon was pilot tested at the site. Test specimens were collected and tested to evaluate durability, compressive strength, and permeability. The samples were extracted by several methods and analyzed to measure the leachable concentrations of organic compounds and metals. Results indicated acceptable physical characteristics. Leachable concentrations of most polynuclear aromatic compounds were decreased.
Lysimeter Data as Input to Performance Assessment Models
Authors: McConnell JW , Rogers RD , Sullivan TM , Jastrow JD , Hicks DS , Brey RR
Published: March 2009

The Field Lysimeter Investigations: Low-Level Waste Data Base Development Program is obtaining information on the performance of radioactive waste forms in a disposal environment. Waste forms fabricated using ionexchange resins from EPICOR-II prefilters employed in the cleanup of the Three Mile Island (TMI) Nuclear Power Station are being tested to develop a low-level waste data base and to obtain information on survivability of waste forms in a disposal environment. The program includes reviewing radionuclide releases from those waste forms in the first 7 years of sampling and examining the relationship between code input parameters and lysimeter data. Also, lysimeter data are applied to performance assessment source term models, and initial results from use of data in two models are presented.
Lime Mortars: Some Considerations on Testing Standardization
Authors: Charola AE , Henriques FMA
Published: March 2009

A set of tests for lime mortars which could serve as the basis for future preservation standards is suggested. The precautions to be taken when preparing the samples for these tests, such as types of molds and curing conditions, are discussed. The various tests necessary to minimally characterize lime mortars for conservation needs are presented while proposing some modifications for adapting present standards to this purpose. The need for establishing reasonable criteria for the perfomance evaluation of lime mortars to be used in architectural conservation is stressed.
Uses of Automated Geotechnical Instrumentation Systems
Authors: Marr WA
Published: March 2009

Developments occurring in electronics and instrumentation promise to lower the cost and improve the reliability of electronic systems to monitor geotechnical instrumentation. The miniaturization of electronics, reduction of power consumption, reduced component cost, and improved component reliability all help to make new instruments possible and geotechnical instrumentation more cost effective.

This paper describes the application of some of these developments to three problems and summarizes the potential benefits to the engineer from their use. The increased capabilities of instrumentation and data acquisition equipment combined with their improved reliability and lower cost will make future applications of geotechnical instrumentation more cost effective.
Apparatus and Method for Field Calibration of Nuclear Surface Density Gauges
Authors: Regimand A , Gilbert AB
Published: March 2009

Nuclear gauge density measurements are routinely used for compliance verification with specifications for road and construction projects. The density of construction materials is an important indicator of structural performance and quality. Due to speed of measurement, flexibility and accuracy, nuclear gauge density measurement methods are becoming the preferred standard around the world.

Requirements dictate that gauges be verified or calibrated once every 12 to 18 months. Presently, there are no field portable devices available for verification of the gauge calibration. Also, the density references used for calibration of gauges, are large and not designed for field portability. Therefore, to meet the present standards, users are required to ship gauges back to a service facility for calibration.

This paper presents results obtained by a newly developed device for field verification and calibration of nuclear density gauges from three different manufacturers. The calibrations obtained by this device are compared to the factory calibration methods and accuracies are reported for each gauge model.
Instrumentation of Dredge Spoil for Landfill Construction
Authors: Byle MJ , McCullough ML , Alexander R , Vasuki NC , Langer JA
Published: March 2009

The Delaware Solid Waste Authority's Northern Solid Waste Management Center is located outside of Wilmington Delaware at Cherry Island, a former dredge disposal site. Dredge spoils, of very low permeability, range in depths up to 30 m (100 feet) which form a natural “liner” and the foundation for the 140 ha (350-acre) municipal solid waste landfill. The soils beneath the landfill have been extensively instrumented to measure pore pressure, settlement and deflections, using inclinometer casings, standpipe piezometers, vibrating wire piezometers, pneumatic piezometers, settlement plates, liquid settlement gages, total pressure cells and thermistors. The nature of the existing waste and anticipated settlements (up to 6 m (19 feet)) have required some unique installation details. The instrumentation data has been integral in planning the landfilling sequence to maintain perimeter slope stability and has provided key geotechnical parameters needed for operation and construction of the landfill. The performance of the instrumentation and monitoring results are discussed.
Field Measurements of Frost Penetration into a Landfill Cover that uses a Paper Sludge Barrier
Authors: Moo-Young HK , LaPlante C , Zimmie TF , Quiroz J
Published: March 2009

Frost penetration is a major environmental concern in landfill design. Freezing and thawing cycles may deteriorate the permeability of the liner or cap. In this study, the depth of frost penetration into a landfill cover that uses paper sludge as the impermeable barrier (the Hubbardston landfill in Massachusetts) was measured using a frost measurement system. A thermistor probe measured the temperature at various depths. Although temperature measurements are important, soil resistivity measurements are required to accurately predict the freezing level, since soil resistivity increases greatly upon freezing. A conductivity probe measured the half bridge voltage between conductivity rings and a ground rod. Data were collected in data loggers.

The data collected from 1992–1996 showed that the frost level did not penetrate the paper sludge capping layer. Heavy snow cover throughout the winters decreased the depth of frost penetration by insulating the landfill. The high water content in the sludge also contributed to the lack of freezing.
Stability Monitoring System for the Fresh Kills Landfill in New York City
Authors: Thomann TG , Khoury MA , Rosenfarb JL , Napolitano RA
Published: March 2009

The Fresh Kills Landfill, located in Staten Island, New York, serves as the repository of all municipal solid waste from the five boroughs of New York City. Because of the existence of compressible soils under most of the filling areas and the urban environment surrounding the landfill, considerable importance is being placed on the relationship between filling operations and the stability of the landfill. As a result of this concern and to address Order on Consent requirements, a program of geotechnical site characterizations, stability analyses, and design and implementation of a geotechnical instrumentation program was undertaken. Geotechnical instruments have been installed within the refuse fill and foundation soils to monitor both the magnitude and rate of change of pore pressure, lateral and vertical movements, and temperature. This paper presents an overview of the subsurface conditions, the overall instrumentation plan for assessing the landfill stability, a description of the various instruments, the performance of these instruments to date, an overview of the collected measurements, and a description of how these measurements are used to monitor the stability.
Integrated Automation of the New Waddell Dam Performance Data Acquisition System
Authors: Welch LR , Fields PE
Published: March 2009

New Waddell Dam, a key feature of the U.S. Bureau of Reclamation's Central Arizona Project, had elements of its dam safety data acquisition system incorporated into the design and construction. The instrumentation array is a reflection of the dam's large size and foundation complexity. Much of the instrumentation is automated. This automation was accomplished while maintaining independent communication connections to major divisions of the instrument array. Fiber optic cables are used to provide high quality data, free from voltage surges that could originate in a nearby powerplant switchyard or from lightning. The system has been working well but there are concerns with a lack of continued equipment manufacturer support.
Selecting Surface Geophysical Methods for Geological, Hydrological, Geotechnical, and Environmental Investigations: The Rationale for the ASTM Provisional Guide
Authors: Saunders W , Benson R , Snelgrove F , Soloyanis S
Published: March 2009

The ASTM Provisional Guide (PS 78–97) for Selecting Surface Geophysical Methods was developed as a guide for project managers, contractors, geologists, and geophysicists to assist in selecting the most likely geophysical method or methods to conduct specific subsurface investigations. Numerous surface geophysical methods and techniques exist that can be used to determine subsurface soil and rock properties and their distribution. These same methods are also widely used to investigate and locate manmade structures such as buried objects and landfills. This paper discusses the general uses of surface geophysics and the use of the provisional guide. This paper is not intended to be used as the guide.

The ASTM Provisional Guide provides direction in selecting the most appropriate geophysical method or methods for a specific application under general site conditions. Secondary methods are also proposed that, under certain circumstances, should be evaluated before a final selection is made. Some typical conditions under which a primary or secondary method might or might not provide satisfactory results are given in the provisional guide. References for further information about selected methods and to method-specific ASTM guides are also provided. Secondary methods usually have less than desired performance, higher cost, or greater labor requirements as compared to the primary methods.
Evaluation of the Effects of Mixed Mode I-II Loading on Elastic-Plastic Ductile Fracture of Metallic Materials
Authors: Laukkanen A , Wallin K , Rintamaa R
Published: March 2009

In order to evaluate the mixed-mode fracture behavior of elastic-plastic metallic materials, experimental tests and numerical calculations were carried out. Since the transition of fracture toughness between opening and in-plane shear modes with ductile materials is a question of controversy, single-edge notched bend (SENB) specimens were subjected to asymmetric four-point bending (ASFPB) to provide various mode portions using four materials: A533B pressure vessel steel, F82H ferritic stainless steel, sensitized AISI 304 austenitic stainless steel, and CuA125 copper alloy. Fracture resistance curves were determined and fractographical studies performed. Numerical studies focused on determining the J-integral and stress intensity factor (SIF) solutions for the experimental program and the Gurson-Tvergaard constitutive model was used to simulate continuum features of the fracture process. The results demonstrate that Mode II fracture toughness of ductile metallic materials can be significantly lower than Mode I fracture toughness. Studies of the micromechanical aspects of fracture demonstrate the factors and variables responsible for the behavior noted in this investigation.