bluuebunny/crossref_metadata_2025 huggingface dataset:
Measuring Risks to Tribal Community Health and Culture
Authors: Harper BL , Harris SG
Published: April 2008

This paper provides a framework for evaluating risks in Indian Country. All cultures depend on environmental quality for their survival, but the health of tribal communities and their individual members is so intertwined with their environment as to be inseparable. The foundation of risk assessment, characterization, and management in Indian Country rests on the federal trust responsibility to protect the people, their homelands, and their natural and cultural resources. Thus, tribal risk assessments must include the probabilities of adverse health, ecological, and cultural impacts in order to be relevant to the affected tribal community and government. This paper presents several environmentally-focused methods for evaluating overall tribal community health risk and eco-cultural health impacts. Elements of this environmentally-based risk assessment include a culturally-sensitive human exposure scenario, ecological risk assessment that includes species of cultural concern, the evaluation of impacts to environmental fonctions and services, measurement of impacts to socioeconomic and sociocultural health, and a risk characterization step that combines of all these risks and impacts in a way that tells the whole story about impacts to the place or resource from the community's trusteeship perspectives. While these elements are likely to be common to most tribal risk assessments, it must also be recognized that each tribe's ecology, history, culture, and government are unique, so every tribal risk assessment will be unique. Several ways to evaluate tribal community health and eco-cultural risk are presented that include environmental fonctions and services, sociocultural and socioeconomic health impact measurement, and risk characterization. It is hoped that by presenting some initial methods for characterizing and comparing risks that are relevant to tribal cultures and communities an interdisciplinary discussion will be sparked that brings together the disciplines of social impact assessment, comparative risk (quality of life), natural resource valuation, public health, and conventional toxicity-based risk assessment.
Effects of Radiation on Materials: 21st International Symposium
Authors: Grossbeck ML , Allen TR , Lott RG , Kumar AS
Published: April 2008

Description

Fifty-nine peer-reviewed papers provide the latest international research on nuclear materials.

Although the primary focus is on pressure vessel steels, including mechanical properties and microstructures, it contains papers on the latest research on fundamentals of radiation effects in materials as well as on stainless steels and nonferrous alloys. It has a truly international flavor containing twenty-six papers from outside the United States.

Sections cover:

• Austenitic Stainless Steels

• Pressure Vessel Steels—Properties and Mechanisms

• Pressure Vessel Steels—Analysis and Prediction

• Ferritic Steels—Model and Low Activation Alloys

• Swelling and Irradiation Creep

• Radiation Effects

• Radiation-Induced Segregation and Transmutation

• Measurement Techniques and Modeling Studies

• Radiation-Induced Segregation and Transmutation

• Measurement Techniques and Modeling Studies

• Ceramic Materials

• Vanadium Alloys

• Zirconium and Copper Alloys
Technology of Floor Maintenance and Current Trends
Authors: Schalitz WJ
Published: April 2008

Description

This new ASTM publication gives you the latest information on ALL ASPECTS of floor polish in easy-to-understand terms.

Ten peer-reviewed papers cover:

A thorough review of the chemistry involved in floor polishes and associated coatings.

Coating maintenance and static coefficient of friction (COF) includes papers that clearly define COF and how it is measured correctly in accordance with ASTM standards. There is also a general review of polish maintenance techniques and a critical paper encompassing the relationship between the static COF of newly applied floor polish and that same finish, which has been subjected to various industry standard maintenance techniques over time.

Legal and regulatory issues discusses the legal aspects associated with a slip incidence, as well as the tools to prevent slip incidents. It also includes an actual case history, which provides a meticulous investigative outline for those involved in the discovery phase of a slip claim; and closes with a review of those regulatory issues that currently effect floor polishes.

STP 1448 will help facilities better manage their floor care program, saving them time and money, while improving the overall appearance and safety. It has a broad base of appeal from the formulation chemist developing polishes to the facilities manager who is looking to better manage their floor care program.
Pesticide Formulations and Application Systems: 23rd Volume
Authors: Volgas GC , Downer RA , Lopez HB
Published: April 2008

Description

Twenty-two peer-review papers give you a broad view of where the pesticide industry may be headed. The recent loss of patent protection for many pesticides has created new opportunities for agricultural chemical manufacturers. Spray adjuvant and inert producers must be more creative in the products they offer; and biotechnology and consolidation are putting pressure on all sectors of the industry. All of these changes have forced formulators to better focus their efforts to offer economic benefits to the end users of their products.

Topics cover:

FORMULATION INGREDIENTS showcases new adjuvant formulations and new inert chemistries. Inert suppliers and researchers presented papers introducing novel formulation tools as well as innovative uses for old inert chemistries.

FORMULATION of PESTICIDES for ENHANCED BIOLOGICAL EFFICACY examines new techniques for adding value and improving performance of products.

APPLICATION and DELIVERY SYSTEMS investigates new, more precise delivery techniques to reduce input costs for growers. This section features both equipment and additive technologies intended to reduce off-target spray drift and enhance deposition of applied sprays.

REGULATORY and ENVIRONMENTAL CONCERNS discusses regulatory and environmental issues, with particular attention to agrochemical and adjuvant formulation.
Air Quality and Comfort Measurement Aboard a Commuter Aircraft and Solutions to Improve Perceived Occupant Comfort Levels
Authors: Fox RB
Published: April 2008

AlliedSignal Aerospace, the manufacturer of the propulsion engines and auxiliary power unit of the BAel46 airframe performed air quality testing in cooperation with the airframe manufacturer, British Aerospace and the customer, Ansett Airlines to identify possible air contaminants entering the aircraft and to evaluate other factors that could affect the comfort of the aircraft occupants. Parameters measured include: volatile and semivolatile organic compounds, aldehydes, carbon dioxide, carbon monoxide, oxygen, relative humidity, temperature, and airflow. The airline evaluated the test results and recommendations and implemented changes in the aircraft air handling system based on these results. Measurement of carbon dioxide levels in the galleys was performed by the airline after modification to verify the effectiveness of the changes. Integrated carbon dioxide levels ranged from 780 to 4700 ppm during flight in the aft galley. Carbon monoxide was not detected by on-line measurement methods, and was at the method detection limit of the integrated sampling techniques. No tri-ortho-cresylphospahte, tri- meta-and-para-cresylphosphate, or trimethylolpropane phosphate were detected on charcoal filters used in the air supply systems to the cabin and cockpit. These filters had been in use for over 1000 hours. Tri-butyl-phosphate was detected, however. Volatile organic contaminants in the supply air and aft galley ranged from 0.11 to 4.43 mg/M3. Summation of odor thresholds ranged from 0.28 to 5.35 for mixtures in air and 9.63 to 88.9 for mixtures in water, indicating that some odors could potentially be detected.
The Airplane Cabin Environment: Past, Present and Future Research
Authors: Space DR , Johnson RA , Rankin WL , Nagda NL
Published: April 2008

The purpose of this paper is to review current information on the airplane cabin environment and other factors that affect passenger and flight attendant comfort and health-related symptoms, and to discuss the need for future research. The paper begins with a discussion of cabin environmental issues reported since the start of large commercial transport category aircraft in the 1930s until the present. Next, the effect of cabin environmental factors in combination with individual and job-related factors are discussed. These multiple factors are the likely predominant influences for flight attendant and passenger perceptions of the cabin environment. The last section discusses possible future research aimed toward improvement of cabin environment comfort given our current understanding and the need to involve airplane manufacturers, airlines, flight attendants and passengers. The comprehensive research would need to include chamber studies designed to evaluate tradeoffs between recirculation rates, humidity, air velocities and temperature; and inflight studies utilizing questionnaires and objective measurement techniques to evaluate multiple factors on passenger and flight attendant comfort and health-related symptoms.
Ozone and Relative Humidity in Airline Cabins on Polar Routes: Measurements and Physical Symptoms
Authors: de Ree H , Bagshaw M , Simons R , Brown RA
Published: April 2008

British Airways (BA) and KLM Royal Dutch Airlines (KLM) occasionally receive reports from flight deck and cabin crew of symptoms regarding the respiratory tract and eyes. Dry eyes, dry throat and respiratory discomfort may be a result of low relative humidity or may be due to raised ozone concentrations. It was decided to do a joint study on this subject. On 24 polar flights (12 KLM, 12 BA), ozone levels and relative humidity were measured and questionnaires were completed by crew members.

Ozone and relative humidity were measured on the flight deck. Flight deck and cabin crew members were asked to indicate if physical symptoms were present, before the flight and toward the end of the flight. The measured ozone concentration for both airlines was highly variable. On KLM flights (with catalytic converters) ozone levels were significantly lower than the ozone level on BA flights (no converters). Although BA aircraft used in this study have humidifiers installed for the flight deck, only on three BA flights was the mean relative humidity over 10%. This suggests that the humidifiers may not have been working properly, and no conclusions regarding their effectiveness can be drawn. Most of the crew members showed an increase in physical symptoms during the flight, as was expected. There was, however, no significant relationship between cabin air parameters and reported physical symptoms.
Roofing Research and Standards Development: 5th Volume
Authors: Wallace TJ , Rossiter WJ
Published: April 2008

Description

Addressing long-standing issues, such as durability, wind resistance, fire resistance, and impact on building energy consumption, this new volume provides ten peer-reviewed papers that provide the latest research results on issues that vitally affect successful long-term roofing performance.

This new publication serves as a valuable resource for all roofing professionals, including contractors, architects, engineers, consultants, building owners, researchers, sales and marketing personnel, product development specialists, and insurers. (ROOF03)
Effect of Friction on the Perceived Mode II Delamination Toughness from Three- and Four-Point Bend End-Notched Flexure Tests
Authors: Schuecker C , Davidson BD
Published: April 2008

Results are presented from a study on the effect of friction on the Mode II delamination toughness as obtained by three- and four-point bend end-notched flexure tests. Finite-element analyses are used to assess the effect of friction on the compliance and energy release rate of the two types of test specimens. Energy release rates are first obtained by a virtual crack closure technique, which can be used to separate the energy lost by the system into that dissipated by friction and that used for crack advance. Energy release rates are then obtained by a simulated compliance calibration procedure. By modeling this commonly used method of data reduction and comparing results with those obtained by crack closure, the ratio of the material's intrinsic toughness to the toughness perceived by users of the tests can be assessed. For both tests, this assessment is made for physically realistic coefficients of friction and, for the four-point end-notched flexure test, as a function of the ratio of inner to outer span length. It is shown that frictional effects on the perceived toughness are considerably larger in the four-point than in the three-point bend end-notched flexure geometry, but that an appropriate choice of the four-point test geometry can make the influence of friction quite small.
Tissue Engineered Medical Products (TEMPs)
Authors: Schutte E , Picciolo GL , Kaplan D
Published: April 2008

Description

Written by an international group of industry experts, regulators, and academics, this new ASTM publication provides the latest data on tissue engineering and the standards available for manufacturing TEMPs.

Twenty-three peer-reviewed papers cover

This new publication serves as a valuable resource for regulators, manufacturers, suppliers, developers, academics, patent examiners, and lawyers.
Environmental Effects on Bonded Graphite/Bismaleimide Structural Joints
Authors: Lubke KA , Butkus LM , Johnson WS
Published: April 2008

There are many advantages to using adhesively bonded joints for aerospace applications, but their potential is not yet realized because not enough is known about the long-term durability of the polymeric adhesives. This paper focuses on the long-term durability of a toughened epoxy used to bond graphite/bismaleimide composites. Double cantilever beam (DCB), end-notched flexure (ENF), and cracked lap shear (CLS) tests were conducted to determine the fracture toughness of the adhesive system before and after environmental exposure. These specimens were exposed to either a hot/dry environment or thermal cycles between -54°C (-65°F) and 104°C (220°F). Unexposed and exposed specimens were tested at room temperature and it was found that the hot/dry environment lowered the fracture toughness of the joints. For the DCB and CLS geometry, unexposed specimens were tested at reduced and elevated temperatures. For some of the DCB and all of the CLS specimens, it was found that the cold temperature reduced the fracture toughness. In order to determine if the environment and temperature combined affect the toughness, the environmentally exposed DCB and CLS specimens were tested at the cold temperature. This combination of cold temperature and environmental exposure significantly lowered the fracture toughness of the material in all adhesive joints tested.
Durability of Building and Construction Sealants and Adhesives
Authors: Wolf A
Published: April 2008

Description

Twenty-eight peer-reviewed papers, reflecting the latest information on sealant and adhesive durability, cover:

Field Experience with Sealed Joints and Adhesive Fixations—discusses a novel secondary drainage system for architectural panel walls, consisting of tubes and joint protection collection reservoirs with one-way valves; the retrofitting of a lock strip gasket system on the façade of a twenty-year old building to create a watertight barrier; and structural silicone glazing systems.

Factors Influencing the Durability of Sealed Joints and Adhesive Fixations—examines the influence of polyester powder coating chemistry on the adhesion durability of silicone sealants; water absorption in cold liquid-applied waterproofing; cleaning and preparation of float glass substrates; relationship between elevated moisture conditions in substrates and the ability of sealants to maintain adequate bond strength; and a comparison of the properties of silyl-terminated polyurethanes with those of traditional polyurethanes.

Durability Studies of Sealants and Adhesives—studies the effect of different foam backer rods on the cure and mechanical performance of sealed joints; HVAC sealant longevity; use of biocides in silicone sealants; case histories of horizontal sealant joint failure investigations; resistance of horizontal joints to concentrated loads; and much more.

Development of New Test Methods and Performance Based Specifications—reviews issues related to the mechanical property characterization of sealants; a systematic approach to a performance-based guide for the selection of crack sealants used in airport pavements; the effect of ambient laboratory climate ageing on material properties used in the FEA modeling of silicone sealants; and the key requirements relevant to any service-life-prediction methodology.
Landscape Ecology and Wildlife Habitat Evaluation: Critical Information for Ecological Risk Assessment, Land-Use Management Activities, and Biodiversity Enhancement
Authors: Kapustka L , Galbraith H , Luxon M , Biddinger GR
Published: April 2008

Description

Eighteen peer-reviewed papers explore the latest information on theoretical and applied ecology, especially as it relates to characterizing environmental risks to wildlife and the requirements of environmental managers.

Until recently, many areas which have low to moderate levels of chemical contamination were subjected to intrusive remediation efforts; the consequence being substantial destruction of existing wildlife habitat and low potential for enhancing better quality habitat at the affected site. This new ASTM publication addresses these issues. Topics cover
Innovations in Controlled Low-Strength Material (Flowable Fill)
Authors: Hitch JL , Howard AK , Baas WP
Published: April 2008

Description

Get the latest information on Controlled Low-Strength Material (CLSM), including new design procedures, current research, unique project applications, and innovative installation techniques. Also known as flowable fill, CLSM is used in place of compacted backfill or unsuitable native soil with the most common uses as pipe embedment and backfill. It continues to gain acceptance in the construction industry and helps create higher quality products.

Eleven peer-reviewed papers highlight the innovations in technology, test methods and material science that have occurred during the evolution of CLSM. Sections include:

Innovative Ingredients—explores the use of non-traditional ingredients in CLSM and determines their suitability or limitations.

Engineering Property Analysis—covers the engineering properties for certain applications of CLSM and includes papers that utilize existing ASTM test methods as well as explored new methods to measure parameters, such as excavatibility.

Pipeline Applications—addresses some of the issues related to pipeline design since one of the most common uses for CLSM is pipe backfill.

As an added bonus you get five current ASTM standards on CLSM developed by Committee D18 on Soil and Rock.

This new publication is a valuable resource for engineers (civil, geotechnical, structural, and transportation); contractors; salesmen, technical service managers, and quality control managers for the ready-mix, admixture, cement, and fly ash industries; FHA and EPA field engineers; and university professors.
Pesticide Formulations and Delivery Systems: The Continued Evolution of Agrochemicals, 24th Volume
Authors: Goss GR , Volgas GC , Salyani M
Published: April 2008

Description

Fourteen peer-reviewed papers address the latest advances in pesticide formulations and delivery systems.

Three sections cover:

Formulations—addresses some of the new challenges in formulating pesticides, including the advent of GMOs (genetically modified organisms) and their effect on the chemical aspects of pest control; new uses of chemicals through formulation changes, liquid and solid formulations and applications, and fluorescent imaging to assess efficiency.

Delivery Systems—discusses delivery and interactions of the pesticide with the target organism, including spray release height and drop size, aerial sprays, and abscission sprays.

Adjuvants—covers the enhancement of pesticide formulation by the use of spray additives.
Skiing Trauma and Safety: Fifteenth Volume
Authors: Johnson RJ , Shealy JE , Ahlbäumer G
Published: April 2008

Description

Eight peer-reviewed papers provide the latest information on snow sport safety, including the means to prevent injury. Topics include:

• Use of the signal detection theory to evaluate the effectiveness of current release value recommendations for alpine ski bindings

• Methods that can minimize time-consuming correction procedures that improve the release retention performance of rental ski equipment

• Insight into the means of choosing an appropriate contrast-enhancing filter to allow better recognition of irregularities in the snow surface by moving skiers

• A case control study of the injury incidence of alpine skiing, telemarking, and snowboarding

• A one-year study of an indoor, artificial slope in Neuss, Germany to evaluate sustained injuries

• A three-year study of skiboarding injuries in comparison to those sustained by classic alpine skiers

• Use of a calibrated radar speed gun to determine the velocity of alpine skiers and snowboarders on "blue square" (more difficult) ski trails at three ski areas widely dispersed in the United States

• A means of predicting the risk of sustaining a knee injury in alpine skiing by computer simulations

STP 1464 is a valuable resource for binding, boot and ski manufacturers; engineers; university professors; physicians, and lawyers; as well as skiing professionals such as ski instructors, ski area managers, and participants in recreational and professional skiing activities.
Zirconium in the Nuclear Industry: Fourteenth International Symposium
Authors: Rudling P , Kammenzind B
Published: April 2008

Description

Forty-one peer-reviewed papers cover all aspects of the fuel cycle. The Basic Metallurgy and Processing sections represent the beginning of the fuel cycle from component design and manufacture. The BWR Corrosion, PWR Corrosion, and Deformation Mechanism sections represent component performance under nominal service conditions. The Primary Failure Mechanism and the Transient and High Temperature Performance sections cover aspects that might end the useful service life of the component. The remaining papers deal with post service life of the component in a dry storage and in a repository environment.
Elemental Analysis of Fuels and Lubricants: Recent Advances and Future Prospects
Authors: Nadkarni RAK
Published: April 2008

Description

Twenty-three peer-reviewed papers examine the latest information on the elemental analysis of fuels and lubricants. Six sections cover:

Overview—discusses total quality management practices advocated for obtaining a "perfect" analysis, including proper staff training, sampling, calibration and quality control practices.

Atomic Spectroscopy—focuses on various aspects of inductively coupled plasma atomic emission spectrometry (ICP-AES), mass spectrometry, and isotope dilution mass spectrometry.

X-Ray Spectroscopy—deals with X-ray fluorescence (XRF), including the determination of sulfur in gasoline and diesel, high-power and low-power wavelength dispersive x-ray fluorescence (WDXRFs), and bench top energy dispersive X-ray fluorescence (EDXRF).

Sulfur Analysis—examines the analyses of low levels of sulfur in petroleum products, particularly gasoline, reformulated gasoline, and diesel; and applications of on-line technology for sulfur determination in fuels.

Mercury Determination—addresses concerns regarding the mercury content of crude oils and its emission through the petroleum refining process.

Other Heteroatoms—discusses the use of atomic emission detection using gas chromatography (AED-GS) to determine elements such as carbon, nitrogen, etc., and much more.
Performance Tests for Hot Mix Asphalt (HMA) Including Fundamental and Empirical Procedures
Authors: Mohammed LN
Published: April 2008

Description

Thirteen peer-reviewed papers provide the latest international and state agency research on the use of performance tests for HMA mixture design and field control.

The papers are arranged in four groups designed to aid the reader in locating papers of interest and to compare and contrast the range of work and opinions presented:

Mixture Simulative Performance Tests—relates to the practical use of some simulative loaded-wheel testers used in identifying rut-prone HMA mixtures.

Mechanistic Test for Quality Control—includes papers in that the mechanistic tests were used in field Quality Control of HMA mixtures.

Mechanistic Tests for Mixture Design—contains several papers relating to the need for mechanistic tests in HMA mixture design.

Application of New Mechanistic Test Methods in HMA Mixture Performance Evaluation—focuses on the use of newly developed mechanistic test methods, which have potentials to be used in HMA mixture performance evaluation.
Methodologies for Linking Nucleation and Propagation Approaches for Predicting Life Under Fretting Fatigue
Authors: Neu RW , Pape JA , Swalla DR
Published: April 2008

During the past 25 years, models for predicting either the nucleation or propagation of fretting fatigue cracks have been developed and verified to a limited extent. Current nucleation models can predict the location of the crack nucleus by correlating the level of fatigue damage with the local state of stress. Fracture mechanics methods are used to predict fretting fatigue crack growth by assuming an initial crack length and orientation. This paper describes multiaxial fatigue criteria based on critical plane approaches that can potentially bridge current nucleation and fracture mechanics methods. Conventional and critical plane models are compared in light of some recent experiments on PH 13-8 Mo stainless steel. A critical plane damage model can predict the orientation and growth direction of crack nuclei. The link between critical plane and fracture mechanics approaches for predicting the early stages of crack propagation is discussed.
Will Nonlinear Backcalculation Help?
Authors: Ullidtz P
Published: April 2008

Backcalculation of FWD data often results in unrealistic layer moduli. The modulus of the subgrade may be two to three times the expected value, and the modulus of an intermediate granular material may be lower than the subgrade modulus. If stresses or strains measured in the pavement are compared with theoretical values, the agreement is often poor.

All theoretical models for calculating pavement response are based on a number of simplifications with respect to reality and must be verified experimentally. Most models assume that all pavement layers consist of linear elastic materials. This paper demonstrates, that treating the subgrade as a nonlinear elastic material, can result in much more realistic moduli and a much better agreement between measured and calculated stresses and strains.

The response of nonlinear elastic materials can be calculated using the Finite Element Method (FEM). A much simpler approach is to use the Method of Equivalent Thicknesses (MET), modified for a nonlinear subgrade. The paper includes an example where moduli backcalculated using FEM, linear elastic theory and MET are compared. Stresses and strains predicted by the three methods are also compared to measured values. For this example it is found that the best agreement between measured and calculated stresses and strains is obtained with MET. FEM results in stresses and strains within the range of measured values, whereas all the stresses and strains calculated with the linear elastic theory are outside of the range of measured stresses or strains.
Small-scale Dynamic Devices for the Measurement of Elastic Stiffness Modulus on Pavement Foundations
Authors: Fleming PR
Published: April 2008

There is an increasing number of small-scale dynamic plate test devices available which reportedly measure an elastic stiflhess modulus for the foundation material under test. They exhibit many similarities in the mechanics of operation although there are many subtle differences in mode of operation, transducers utilised and analysis procedure, which lead to variations in the measured results. Three such devices are reviewed in some detail in this paper. Findings from a laboratory investigation of dynamic plate test mechanics are presented which highlight the important role of inertia, both for the device and the soil. Field derived data are then presented which demonstrate the comparative performance of two devices to the FWD and these are then discussed in light of the laboratory findings. Conclusions are then drawn and recommendations made for the key functional requirements of such tests.
A Comparison of the Rolling Weight Deflectometer with the Falling Weight Deflectometer
Authors: Briggs RC , Johnson RF , Stubstad RN , Pierce L
Published: April 2008

A prototype Rolling Weight Deflectometer (RWD) has been designed and produced for testing airfield pavements. The RWD is a trailer mounted device that continuously measures maximum pavement deflections under a load wheel under moving conditions. The RWD was originally designed to perform measurements at a maximum speed of 10 kph (6 mph) with load of up to 222 kN (50,000 lb.). The RWD was recently modified to collect deflections at an increased speed of 32 kph (20 mph) under a 40 kN (9000 lb.) wheel load. It is anticipated that a highway version of the RWD will be produced jointly by Quest Integrated and Dynatest Consulting, Inc., within the next two years that will collect deflections at highway speeds of 70 to 80 kph (45 to 50 mph).

In September of 1997, the Washington State Department of Transportation completed a test comparing the deflection results from the RWD and the WSDOT FWD. The testing was conducted on a newly constructed roadway that consisted of 165 mm (6.5 inches) of asphalt concrete over 400 mm (16 inches) of crushed stone base. At the time of testing the roadway had received only construction traffic. The RWD produced deflections that compared closely with the Falling Weight Deflectometer both in magnitude and variation along the highway. The results of this comparison test are documented in the paper.
Flexible Pavement Condition Evaluation Using Deflection Basin Parameters and Dynamic Finite Element Analysis Implemented by Artificial Neural Networks
Authors: Kim YR , Lee Y-C , Ranjithan SR
Published: April 2008

This paper presents a methodology based on deflection basin parameters and artificial neural networks (ANNs) for processing dynamic falling weight deflectometer (FWD) measurements to estimate layer moduli and condition. Two-dimensional, dynamic, finite element analysis using the ABAQUS program was employed to develop the deflection information for this study. Unlike the majority of the existing backcalculation programs that iteratively adjust all the layer moduli to match the measured deflections, the proposed method first determines the subgrade modulus by means of two deflection basin parameters, Base Damage Index and Shape Factor F2, and then applies the estimated subgrade modulus and other parameters as input variables to a trained ANN to estimate the upper layers’ moduli. Procedures in predicting layer moduli for both two- and three-layer pavement systems are presented. Field FWD measurements were analyzed both by this method and by the MODULUS program, the results of which assess the capability of the proposed method. Effects of discontinuities in the asphalt layer on the resulting FWD deflections were also studied using the finite element method. It was discovered that distresses in the asphalt layer may be detected using two deflection basin parameters, Shape Factor F2 and AREA.
An Overview and Discussion of Basic Methodology for Fatigue
Authors: Dowling NE , Thangjitham S
Published: April 2008

This paper broadly reviews the stress-based, strain-based, and crack growth aproaches to fatigue life prediction, and it attempts to suggest some choices and variations of these that might enhance their inclusion in undergraduate education and their more routine use by practicing engineers. For the stress-based approach, emphasis should shift toward the use of data on actual components, and it should be recognized that damage below the usual fatigue limit may occur. Also, evaluation of mean stress effects by the modified Goodman diagram should be replaced by other methods. The usefulness of the strain-based approach for simple situations may be extended by adding empirical adjustments for surface finish and size. It may also be desirable to lower the long-life end of the strain-life curve to obtain agreement with limited component test data, producing a component-specific strain-life curve. Use of the crack growth approach is hampered by the lack of a widely accepted set of materials constants for describing da/dN versus ΔK curves. It is recommended that this situation be remedied by representing the intermediate growth rate region with a Paris-type exponent, an associated coefficient, and a third constant that characterizes the sensitivity to R-ratio according to the equation of Walker. Limits or asymptotic behavior for the low and high growth rate regions should then be handled separately.
Performance and Durability of the Window-Wall Interface
Authors: Hardman BG , Wagus CR , Weston TA
Published: April 2008

Description

Get the latest information available on the performance and durability of the window-wall interface. STP 1484 offers new research, exhaustive testing, and the creation of installation standards which attempt to identify installation methods and construction sequencing, to integrate a variety of fenestration products into a variety of wall claddings.

Ten peer-reviewed papers cover:

• Integration of windows or doors with their related interfaces—lashings, sealants, claddings, and more

• Considerations of weather, exposure, job site conditions

• Compatibility or incompatibility of adjacent and integrated materials

• Product testing and the testing of installation methods and techniques

• Role that permeability plays in the selection of materials

• Ability or inability of self-adhered materials to maintain their original adhesion properties, long-term serviceability, and durability.

This new publication provides the vital information you need to write specifications, create or interpret standards, evaluate materials for product selection, and recommend changes to the building codes.
Sulfur Concrete for Corrosion-Resistant Sewer Pipe
Authors: Vroom AH , Aarsleff L , Vroom CH
Published: April 2008

Experience to date shows sulfur concrete to have many advantages over hydraulic cement concrete for sewer pipe. Its durability, high corrosion-resistance, impermeability and high mechanical strength, combined with its high volume production capability, make it an economical, long-lasting material. Other properties include high abrasion resistance and extremely high resistance to fatigue.

Sulfur concrete sewer pipe can be dry-cast, wet-cast or spun using conventional concrete pipe molds. The hot mix develops its strength simply on cooling, no curing being required.

Details of mix design and preparation are described. Examples of commercial-scale production of pipes and tanks are presented.

The need for modified ASTM Standards for such pipe and related products is discussed.
Intelligent Technology for Concrete Pipe in the New Millennium
Authors: Hill JJ , Kurdziel JM , Nelson CR , Nystrom JA
Published: April 2008

Precast concrete pipes were widely used even before the beginning of the twentieth century. By 1930, the currently used design and installation standards for concrete pipes had been empirically developed by Drs. Marston and Spangler. Nearly thirty years ago, the American Concrete Pipe Association began research on a more rational design method that evaluated the contributions of the strength of both the pipe and underlying soil. From that research, the design program Standard Installation Direct Design (SIDD) was developed.

In 1997, engineers at the Minnesota Department of Transportation successfully used the newly developed technology to update their standard practice for installing concrete pipe. A test, using native soils and simplified construction details, compared performance of the Marston-Spangler and SIDD installations.

Acceptance of direct design methods for concrete pipes is just the beginning of advancement of new technology for construction of pipelines. Rapid development of the internet, wireless communication links, geographical positioning systems, expert systems, and miniaturized testing equipment makes it possible for a manager of a construction project to integrate all phases of design, construction, and maintenance into a centralized information system. This paper describes how construction managers might use technology to mesh existing components of construction activities into an Intelligent Construction System.
Relationships of Test Methods and Standards Development to Emerging and Retrofit CFCC Markets
Authors: Barnett TR , Ojard GC , Cairo RR
Published: April 2008

The evolutionary path of ceramic matrix composites (CMCs) to viable candidate materials for current engineering designs of today and tomorrow has been littered with appropriate and inappropriate theoretical models, useful and useless test methods, and hopeful and hopeless materials systems. As continuous fiber ceramic composite (CFCC) material systems have been introduced, theoretical models and practical test methods have been proposed (and adopted) to characterize their behavior. Often these materials are targeted for specific applications intended to exploit the bulk CFCC as well as its constituent properties.

The unique position and expertise of the author's employer, a private research laboratory, have enabled an up-close and detailed perspective on not only CFCCs and their characterization but also the targeted engineering applications. In this paper, a case study will be discussed regarding characterization of a CFCC for a particular application; a high temperature combustor liner in a gas turbine engine. The potential for standardized methods will be reviewed.
Use of Unload/Reload Methodologies to Investigate the Thermal Degradation of an Alumina Fiber-Reinforced Ceramic Matrix Composite
Authors: Campbell CX , Jenkins MG
Published: April 2008

Oxide fiber-reinforced/oxide matrix continuous fiber-reinforced ceramic composites (CFCCs) have the potential of resisting high-temperature degradation in the increasingly aggressive environments of the emerging applications of this still-evolving class of materials. However, a major design and processing limitation of CFCCs is the lack of information on the in situ properties and performance of the composite constituents (i.e., fibers, interphase, and matrix). Monotonic and unload/reload tensile tests were conducted in ambient air on CFCC test specimens in the unexposed condition and after 10- and 100-h exposures at 600, 800, 1000 and 1200°C. Two methodologies were used for the evaluation of the unload/reload tensile test results to extract constitutive property data on the residual stress state, interfacial shear stress, interfacial debond resistance, and damage state of the composite. The phenomenological approach is based on the stiffness degradation of the composite with incremental load steps. The analytical approach is based on the shape of the unload/reload hysteresis loops.
Oxidation Behavior of Non-Oxide Ceramics in a High-Pressure, High-Temperature Steam Environment
Authors: Ferber MK , Lin HT , Keiser J
Published: April 2008

This paper provides a review of two recent studies undertaken to examine the oxidation behavior of monolithic SiC and SiC-SiC composites in simulated and actual gas turbine environments. In the first study, a high-pressure and high-temperature test facility was used to expose a variety of structural ceramics and ceramic matrix composites to 15% water vapor carried in an air environment at 10 atm of total pressure and 1204°C. The second study involved the exposure of a SiC-SiC combustor liner in an industrial gas turbine for approximately 2300 h at a total pressure of 10 atm and peak liner temperature of 1150°C.

In the two studies microstructural analyses were used to measure the rates of both silica scale formation and SiC recession. These experimentally determined rates were then compared with values predicted from established oxidation/volatilization models. The estimates of the temperature and pressure sensitivities of the oxidation and volatilization rate constants, required for this comparison, were obtained from the literature. For the case of the combustor liner, the recession rate of SiC was well described by the model. However, the predicted rates of scale formation in both studies were significantly lower that the corresponding experimental values. Possible reasons for this discrepancy are addressed.
Impact Performance Characteristics of Hockey Helmets with Liners of Differing Thicknesses
Authors: Bishop PJ
Published: April 2008

Recently professional players have been modifying their hockey helmets by using liner materials which have a thickness of only 9.5 mm compared to the usual 16 mm thickness of liner found in many Canadian Standards Association (CS A) approved helmets. Since helmet performance is related to both the stiffness and thickness of the liner material, this study was conducted to test the hypothesis that the performance capability of helmets with thinner liners is substantially less than that of CSA approved helmets. Five helmet models with vinyl nitril liners of the same density but of two differing thicknesses (9.5 mm and 16 mm) were subjected to 3 successive impacts each on the side location using a standard monorail drop test apparatus. The headform was a rubberized epoxy alloy from which the headform acceleration and Severity Index were determined. The average peak acceleration for the third impact for the regular liner (RL) was 261±13g compared to 367±28g for the thin liner (TL). The average Severity Indices associated with these impacts were 1025±73 for the RL and 1615±175 for the TL. Using the graph of Prasad Mertz (1985) a Severity Index (SI) of 1000 would put about 12% of the population at risk for a serious head injury while an SI of 1600 would put the risk at about 48% of the population. Clearly, when helmet liners of the same density but with different thicknesses are used, the risk of injury is magnified with the thin liner. To improve head protection with a thin liner additional research using stiffer materials is required.
Variability in Field Density Tests
Authors: Noorany I , Gardner WS , Corley DJ , Brown JL
Published: April 2008

This paper describes a comparative study of the three most commonly used field density tests: sand-cone, nuclear, and drive-cylinder. In order to evaluate the range of variability of these tests, a large-scale soil compaction apparatus was constructed so that soil could be compacted to a known water content and dry density under close laboratory control conditions before running field density tests. The equipment consisted of a 4-ft (122-cm) mold, and a hydraulic system for compacting the soil in ten 4-in. (10-cm) thick layers inside the mold. A cohesive soil with gravel up to 3/4-in. (19 mm) in size was used. Five series of tests were performed on this soil compacted to five different water contents and dry densities. In each series, side-by-side sand-cone, nuclear, and 3-in. (7.6-cm) drive-cylinder tests were made. It was found that sand-cone test results were closer to the placement values than the nuclear test results. This was partly due to inaccuracies in water content readings by the nuclear device. When the water content data measured by the nuclear device were ignored and the placement water contents measured by oven-drying were used instead, the results of the nuclear tests became more accurate, but the range of variability in the measured data did not decrease significantly. The drive-cylinder test had a bias toward underestimating the actual field density, primarily due to sampling disturbance. Despite careful control of test conditions, data from all three test methods had a wide range of variability.
Compaction Conditions and Scale-Dependent Hydraulic Conductivity of Compacted Clay Liners
Authors: Benson CH , Boutwell GP
Published: April 2008

A database was compiled containing index properties, compaction data, and hydraulic conductivity data from 51 clay liners. The hydraulic conductivity data included large-scale field measurements (KF) and small-scale laboratory measurements (KL) on specimens collected from the field in 74-mm-diameter sampling tubes. Analysis of the database shows that KF is comparable to KL when compaction is wet of the line of optimums, but KF can be up to 266 times larger than KL when compaction is dry of the line of optimums. Similar results were obtained from a stochastic simulation model. Discrepancies between KF and KL exist when macropores are present (i.e., compaction dry of the line of optimums), because macropores are inadequately represented in small laboratory specimens. To achieve, KF ∼ KL compaction specifications should require that the percentage of data falling wet of the line of optimums (Po) exceed 80–90% and the difference in initial saturation (ΔSi, which is the mean degree of saturation at compaction less the degree of saturation corresponding to the line of optimums) exceed 2 to 4%. A “line of optimums” compaction specification is recommended to facilitate achieving these recommended values for Po and ΔSi.
Life Prediction of PPS Composites Subjected to Cyclic Loading at Elevated Temperatures
Authors: Loverich JS , Russell BE , Case SW , Reifsnider KL
Published: April 2008

Combinations of failure mechanisms are frequently encountered in the life prediction of composite materials. A life prediction methodology is developed and applied to one such failure mechanism combination. This method uses experimental data and analytical tools to predict the long-term behavior of a composite under service conditions. The prediction scheme is based on the assumption that damage accumulation progressively reduces the remaining strength of a composite. An overview of the fundamental concepts of the life prediction method is presented. The method is used to model the elevated temperature fatigue behavior of a unidirectional AS-4 carbon fiber/PolyPhenylene Sulfide (PPS) matrix composite material. The nonlinear combined effects of time at elevated temperature and fatigue are taken into account by considering elevated temperature tensile rupture and room temperature fatigue behavior. The life prediction for the combined loading is compared to 90°C tensile-tensile fatigue data. This comparison shows good correlation between the prediction and data and demonstrates the method's effectiveness in life prediction modeling.