bluuebunny/crossref_metadata_2025_split huggingface dataset:
Data Standardization--The Key to Effective Management
Authors: Wagner CR 
Published: March 2009

Effective management of the nation's water resources is dependent upon accurate and consistent hydrologic information. Before the emergence of environmental concerns in the 1960's, most hydrologic information was collected by the U.S. Geological Survey and other Federal agencies that used fairly consistent methods and equipment. In the past quarter century, however, increased environmental awareness has resulted in an expansion of hydrologic data collection not only by Federal agencies, but also by state and municipal governments, university investigators, and private consulting firms. The acceptance and use of standard methods of collecting and processing hydrologic data would contribute to cost savings and to greater credibility of flow information vital to responsible assessment and management of the nation's water resources.
This paper traces the evolution of the requirements and uses of open-channel flow information in the U.S., and the sequence of efforts to standardize the methods used to obtain this information in the future. The variable nature of naturally flowing rivers results in continually changing hydraulic properties of their channels. Those persons responsible for measurement of water flowing in open channels (streamflow) must use a large amount of judgement in the selection of appropriate equipment and techniques to obtain accurate flow information. Standardization of the methods used in the measurement of streamflow is essential to assure consistency of data, but must also allow considerable latitude for individual judgement to meet constantly changing field conditions.
Is Modeling in Tribology a Useful Activity?
Authors: Barber JR 
Published: March 2009

The typical tribological system is very complicated and many of the contributory fundamental process are themselves poorly understood. Attempts to apply traditional mechanical modeling to such systems generally fail from lack of appropriate data and from an inability to describe the complexity of the real system. Even if such an attempt were to succeed, there would often be so many independent parameters required to describe the system that suitably comprehensive results could not be conveniently presented.
Recognizing these difficulties, publication and funding priorities should emphasize the importance of deducing approximate but generally applicable rules for the behaviour of broad classes of systems. Researchers should endeavour to determine which features of the real system are most influential in determining its behaviour, with a view to guiding the designer in a choice of model which is simple enough to analyze, but which retains the essential physics of the problem.
Use of Abstraction in Creating Data Dictionaries for Materials Data Banks
Authors: Sargent PM 
Published: March 2009

Construction of all databases requires an underlying “data model,” either implicit or explicit. The different options for data models for materials property data are an appropriate subject for standardization because they require agreed specifications for the formats of catalogs, data dictionaries, or thesauri. An understanding of these underlying data models is also crucial in deriving useful and flexible data interchange formats. This paper shows that a “layered” approach in constructing data dictionaries can be helpful both in setting up databases and in defining interchange formats.
The problems of adopting new software techniques and accepting innovations in models for materials data have a powerful effect on how best to present such ideas such that they are of most use.
Promoted Ignition-Combustion Behavior of Selected Hastelloys® in Oxygen Gas Mixtures
Authors: Zawierucha R , McIlroy K , Mazzarella RB 
Published: March 2009

Promoted ignition and more recently promoted combustion are terms which have been used to describe a situation where a substance with low oxygen compatibility ignites and supports the combustion of a more ignition resistant material. Previous papers by Union Carbide have reported on the investigation of this phenomenon as it related to carbon steel, 316L stainless steel, aluminum-bronze, Carpenter® 20Cb-3, Incoloy® 65, Inconel® 625 and Haynes® 25. In this paper, additional data will be presented on the promoted ignition-combustion behavior of various Hastelloy® type materials, which are significant engineering alloys that may be encountered in or considered for gaseous oxygen applications in severe environments.
In this investigation, alloys have been evaluated via both flowing and static (fixed volume) approaches using the rod configuration used in the joint ASTM-CGA-NASA program. Static tests have been conducted in a vessel of the same volume as the apparatus used by NASA in the joint ASTM-CGA-NASA test program conducted at WSTF and also in a larger 6.0 liter vessel. Oxygen-nitrogen gas mixtures with purities ranging from approximately 40% to 99.7% at pressures of 3.55 MPa to 34.6 MPa were used in the comparative studies of five Hastelloy® compositions.
As an adjunct to this investigation, neural network techniques were utilized in the analysis of the data. Neural network analysis is an artificial intelligence technique which mimics the human brain. The data generated in this investigation and other work was incorporated into a predictive tool.
Promoted Ignition-Combustion Behavior of Precipitation Hardened Engineering Alloys
Authors: McIlroy K , Zawierucha R 
Published: March 2009

Promoted ignition and more recently promoted combustion are terms which have been used to describe a situation where a substance with low oxygen compatibility ignites and supports the combustion of a more combustion resistant material. Previous papers as well as a companion paper by the authors have reported on the investigation of this phenomenon as it related to carbon steels, 316L stainless steel and a number of significant engineering alloys.
Within oxygen systems there are a number of engineering alloys which receive precipitation hardening heat treatments in order to develop desired mechanical properties. Although flammability data on some of these alloys have been reported in the literature, the effect of heat treatment on flammability tendencies has not received much attention. Metallurgical processes such as solution heat treatment and precipitation hardening may affect the distribution and relative proportions of metallic and intermetallic phases; thereby influencing mechanical and in some cases physical properties. Several recent papers have suggested that metallurgical processes should receive more attention in flammability studies.
The alloys selected for investigation in this study were 17-4PH stainless steel and Inconel® 718. Both alloys may be strengthened via precipitation hardening processes. Promoted ignition-combustion tests of these alloys in both the solution annealed and precipitation hardened conditions were conducted in flowing and static (fixed volume) testers using the rod configuration used in the joint ASTM-CGA-NASA program. The flammability tests were conducted in oxygen-nitrogen gas mixtures with oxygen purities ranging from approximately 40% to 99.7% at pressures of 0.79MPa to 34.6MPa.
Thermodynamic and Fluid Mechanic Analyses of Rapid Pressurization in a Dead-End Tube
Authors: Leslie IH 
Published: March 2009

Three models have been applied to very rapid compression of oxygen in a dead-ended tube. Pressures as high as 41MPa (6,000psi) lead to peak temperatures well in excess of the autoignition temperature (750K) of polytetrafluoroethylene (PTFE). These findings are in accord with experiments that have resulted in ignition and combustion of the PTFE, leading to the melting and/or combustion of the stainless steel braiding and catastrophic failure.
A purely thermodynamic model assumes filling to be complete upstream of a flow-limiting orifice before any gas passes through the orifice. Results show that peak temperatures as high as 4,800K can result from recompression of the gas after expanding through the orifice. An approximate transient model without an orifice was developed assuming an isentropic compression process. Results indicated that fill times can be considerably shorter than valve opening times. The third model was a finite difference, 1-D transient compressible flow model. Results from the code show the recompression effect but predict much lower peak temperatures than the thermodynamic model. The difference is due mostly to the complete lack of mixing in the thermodynamic model.
Test Methods and Interpretation of Results for Selecting Non-Metallic Materials for Oxygen Service
Authors: Vagnard G , Delode G , Barthélémy H 
Published: March 2009

In spite of their easier ignition capability compared to metals and ceramics, non-metallic materials are often used in oxygen atmospheres because of their specific properties and, consequently, miscellaneous methods have been developped to evaluate their ignition risks which depend on their service conditions.
The main test methods implemented at “L'AIR LIQUIDE — Centre de Technologie et d'Expertise” i.e., the “bomb test” (determination of autogenous ignition temperature at high oxygen pressure), the gaseous oxygen pneumatic impact test (adiabatic compression test) and the liquid oxygen mechanical impact test will be presented first.
Then, we will give our interpretation of the results which show that: for use with high-pressure oxygen gas (up to 24 MPa), it is best to use materials with spontaneous ignition temperature at 12 MPa greater than or equal to 400°C ; however, this may not be a sufficient limit if extreme ignition sources can be expected ; on the other hand, it may not be possible to respect this limit if a compromise is required between the qualities of the product for which it is used and its resistance to ignition ; the following precautions must be taken in either of these cases: the equipment must be well-designed (small quantities of organic materials, protected wherever possible from the impact of the gas stream and in integral contact with their metal support), additional tests must be made on this equipment (such as adiabatic compression tests), a precise analysis of hazards must be made and types of use for which no incidents have been reported should be considered; for use with liquid oxygen, the materials must at least successfully pass the impact drop test at an energy level of 100 Joules.
The North Dakota Dot Pavement Management System Implementation Process
Authors: Cation KA 
Published: March 2009

In a recent mandate issued by the Federal Highway Administration (FHWA), State Highway Agencies were required to have operational Pavement Management Systems by January 1993. The objectives of this mandate included the development of objective decision processes which would determine the cost-effectiveness of various rehabilitation strategies in order to evaluate their impact on the overall condition of the State's pavement network. In 1989, the State of North Dakota hired a consultant to assist them with the development of analytical software which would utilize their extensive pavement database and satisfy the requirements of the FHWA mandate.
There were two important features to the North Dakota System development. The first involves the DOT's use of an active Steering Committee, or User's Group, made up of individuals from throughout the organization. The group was intimately involved with the system development through the use of subcommittees who participated in all aspects of the system development. The group was very influential in ensuring the successful implementation of the system by addressing the “Institutional Issues” which play a large role in the system's overall success within the organization. This served to increase the committee's commitment to the project as well as begin to familiarize the organization with the system in a gradual manner.
The second important characteristic of the North Dakota implementation was the State's decision to provide an opportunity for the cities and counties within the State to initiate their own pavement management implementations through a “piggy-back” arrangement with the DOT. For a minimal fee, local jurisdictions were invited to participate in the pavement management program and implement a more limited version of the State's system within their organization. Each participating jurisdiction was thoroughly trained on sectioning and data collection procedures, data entry, and data analysis. Following completion of the training session, the jurisdictions received a complete system which was completely compatible with the State system, easily facilitating the exchange of information between the two agencies.
Design and Construction of Asphalt Concrete Using Polymer Modified Asphalt Binders
Authors: Shuler TS , Hanson DI , McKeen RG 
Published: March 2009

A full-scale experimental pavement was constructed to compare low temperature cracking performance of asphalt concrete containing two types of styrene block copolymers and an ethylene-based polymer each at two levels of concentration in a relatively soft asphalt cement. The experiment was designed to compare field performance with observed behavior in the laboratory.
Samples of all binders and mixtures were collected during construction and laboratory tests were conducted using actual materials placed in the field.
Mixture tests were limited to Marshall, resilient modulus, and ASTM D4867 moisture sensitivity. Results indicate a high resistance to water damage and relatively high Marshall stabilities for all mixtures evaluated. Marshall test results were highly variable and no apparent differences between materials could be resolved using Marshall parameters. Resilient modulus was conducted at three temperatures, but small differences in this property were not conclusive regarding effects of polymer modification on temperature susceptibility of the mixtures. Variability in resilient modulus measurements was high for certain mixtures.
Experience gained in the laboratory and field during design and construction of this experimental pavement has provided information regarding recommended practices when using certain polymer modifiers during construction of asphalt concrete. For example, conventional viscosity-temperature relationships developed with capillary viscometers were misleading regarding establishment of mixing and compaction temperatures. The predicted temperatures were higher than required for mixing and compaction of the polymer modified mixtures. This experience suggests that new techniques should be developed for establishing appropriate mixing, laydown and compaction temperatures for polymer modified asphalt mixtures.
Application of Size Exclusion Chromatography to Polymers and Coatings
Authors: Kuo C-Y , Provder T 
Published: March 2009

The newer coatings technologies of waterborne, high solids, powder, and radiation curable coatings generally require high molecular weight latex polymers or strategically designed low molecular weight polymers, oligomers, and reactive additives. The design of these resin materials requires molecular weight distribution (MWD) information in the very high and very low molecular weight ranges which are accessible by size exclusion chromatography (SEC). In addition, there is a need for compositional distribution information as a function of molecular weight, particularly for oligomers; absolute MWD information, particularly for water-soluble polymers; and chain-branching information for high molecular weight polymers.
In this paper, the SEC separation mechanism, molecular weight calibration methods including the use of hydrodynamic volume, data treatment methods, and polymer chain-branching determination will be discussed. The use of molecular size sensitive detectors (viscometer, light scattering) and compositional sensitive detectors (UV-visible, IR) will be discussed in the context of illustrative qualitative and quantitative examples. The practice of high resolution SEC analysis of oligomers will be discussed and illustrated with problem-solving examples.
Practical Applications of Gas Chromatography in the Paint and Coatings Industry
Authors: Young FX 
Published: March 2009

Gas chromatography (GC) is an established analytical technique which is useful for the characterization of coatings and related materials. With the introduction of chemically inert and thermally stable fused silica capillary columns, many volatile and semivolatile polar compounds can now be chromatographed easily. Nonvolatile polymers used in coatings can be routinely characterized by pyrolysis-gas chromatography-mass spectrometry (pyrolysis-GC-MS).
Practical examples are presented showing how GC and pyrolysis-GC-MS can be used to monitor the quality of raw materials, resolve manufacturing problems and field complaints, and aid in the reverse engineering of various products. Routine quantitative GC methods, such as the analysis of coalescent agents in latex paint and residual monomers in latex emulsions, are illustrated. Examples are given showing how GC is used for the analysis of raw materials like mineral spirits and fatty acids. GC is also used to characterize and quantitate additives like low molecular weight nonionic surfactants, waxes and oils, and mildewcides. Headspace sampling is used for identifying odor problems and analyzing samples for which solvent dilution is not appropriate. The usefulness of pyrolysis-GC-MS in the characterization of several different types of polymers is demonstrated.
Mechanical Properties of Hard Tissue Adhesive Films
Authors: Moon PC , Moxley JW , Haas TW , Chang YH 
Published: March 2009

Improved dental adhesives for bonding to the dentin of teeth have been introduced that may have the potential of bonding to bone. The properties of these materials have not been characterized. The purpose of this study was to measure the mechanical properties of three of these adhesive resins, Universal Bond II (UB2), Scotchbond II (SB2), and Tenure (Ten). These measurements were used to determine if the bond strengths approached the cohesive strengths of the materials and for finite element evaluation of polymerization shrinkage bond stress. Thin resin films (130 ± 5 μm) were cast and cured between microscope slides. The films (N=6) were tested using an Instron tensile test at 2.5 mm/min and a Rheometric Solids Analyzer (1 Hz) after 24 hours in air. The breaking strength and maximum strain of TEN, SB2, and UB2 were 19.0 ±2.8, 17.4 ± 3.7, 10.7 ± 1.0 MPa, and 8%, 6%, and 32%, respectively. The strength of UB2 was significantly different at P &lt; 0.05. Rheometric analysis gave the dynamic (1 Hz) and static elastic modulus, tandmax, and Tg for TEN, SB2, and UB2 as follows: 1100, 1000, 600 MPa; 620, 530, 370 MPa; 0.20, 0.67, 0.21; and 75°C, 79°C, 84°C, respectively. The measurements were the first reported for properties of these materials.
The use of the measured mechanical properties in the finite element models to calculate the interfacial stress of bonded composite restoration demonstrated that the maximum shrinkage stresses were reduced below the bond strengths by using thick resin bonded films of 125 μm to allow stress relaxation. The finite element models indicated that variations in the maximum shrinkage stress and its location occurred depending on the curing conditions. These finite element analyses were the first models of curing shrinkage applied to dental bonding.
Characterization and Quantification of Fretting Particulates Generated in Ceramic/Metal and Metal/Metal Modular Head/Taper Systems
Authors: Bhambri SK , Gilbertson LN 
Published: March 2009

The use of modular head/Morse taper joints in total hip replacements has become a preferred surgical practice in consideration of the flexibility in surgical procedures and reduced inventory. The modular joints also offer an advantage in selection of appropriate material for components of a prosthesis depending upon the performance requirements. These modular joints have performed successfully in vivo for well over a decade. Recently, however, the release of fretting wear particulates from prosthetic implants in total hip arthroplasty has received greater attention, and a concern has been expressed for the modular head/taper joint to be a source of metal debris.
In this paper, an experimental setup is described for conducting fretting/corrosion fatigue testing of modular head/taper assemblies in simulated body environments. The test setup consisted of a special cell designed to contain simulated body environment and to retain all particles greater than 0.20μm, generated due to fretting fatigue. For this purpose, in-line filters were used and the environmental chamber was made of acrylic material to avoid any contamination. The test environment was aerated Ringer's solution circulated in a closed loop at 37°C. The fatigue load was applied on the head in 15°C mediolateral anatomic orientation. The functional capabilities of this setup was demonstrated by testing alumina ceramic and cobalt-chromium-molyb-denum femoral heads fitted on titanium alloy tapers, at a fatigue load of 5.34 kN and a stress ratio of 0.1. The results are summarized in terms of characterization and quantification of any particulates generated, and surface topographical changes on both head and taper contact surfaces.
Improved Methods for Asphalt-Overlaid Concrete Pavement Backcalculation and Evaluation
Authors: Hall KT , Darter MI 
Published: March 2009

Structural evaluation is perhaps more difficult for asphalt-overlaid concrete (AC/PCC) pavement than for any other pavement type. This is partly due to the inadequacies of available tools to analyze the complex behavior of composite pavement structures, and partly due to the lack of guidance available for interpretation of structural analysis results. Guidelines for deflection data analysis and interpretation of backcalculation results for AC/PCC pavement are presented in this paper.
In recent research, a procedure has been developed for backcalculation of concrete slab and foundation moduli from deflections measured on asphalt-overlaid concrete (AC/PCC) pavement. This backcalculation method quickly and repeatably produces results consistent with other backcalculation methods and consistent with observed distress and the condition of cores, with efficiency and repeatability unmatched by iterative or database search methods.
Guidelines were also developed for practical interpretation of the backcalculation results, by this or any other reliable method. These guidelines were developed for evaluation of AC/PCC pavement but are also relevant to PCC pavement evaluation. Backcalculation can yield many useful results, including mean PCC slab and foundation moduli, variability in moduli, percentage of backcalculated moduli below a selected critical level, identification of specific areas with unusually high or low moduli, and the relationship of slab and foundation moduli to type, quantity, and severity of distress.