bluuebunny/crossref_metadata_2025_split huggingface dataset:
ASNT Recommended Practice for Nondestructive Testing Personnel Qualification and Certification (SNT-TC-1A) and Its Use
Authors: Berry FC 
Published: March 2009

The need for standardization of nondestructive testing personnel qualifications brought about the writing of the American Society for Nondestructive Testing (ASNT) Recommended Practice for Nondestructive Testing Personnel Qualification and Certification (SNT-TC-1A). The choice of an organization to prepare such a document was based on ASNT's prime interest and its membership being a cross-section representation of industry and government organizations within the United States.
ASNT Recommended Practice SNT-TC-1A is a combination of various requirements taken from American government and industry specifications. This document is designed to be adapted by any user to fit a specific need.
ASNT offers an additional service of review or examination of personnel for the qualification as a Level III Nondestructive Testing person.
Standards for Real-Time Systems Used with Penetrating Radiation
Authors: McKee WJ 
Published: March 2009

In the area of radiography, there has been a substantial effort to find a reasonable approach in formulating standards to aid us in determining the level of performance that can be expected from a certain group of equipment and then determine desired or recommended procedures that would provide the optimum results obtainable with the equipment described.
We now approach the area of real-time systems, those of electronic imaging and gaging, for similar purposes. In many ways, there are close correlations to the classic film techniques of radiography but there are also many areas that are unique to these electronic systems, and we must deal with them now.
Ultrasonic Testing Standards—Overview
Authors: Bobbin JE 
Published: March 2009

Ultrasonic testing is used extensively for flaw detection, thickness measurement, and determining material properties. Now, as the field reaches maturity, there is a greater need to obtain quantitative data from the test itself. This need, in turn, has been followed by an implied need for standardization.
The goal of standardization, for whatever reasons, is laudable. In ultrasonics it covers three possible areas of interest which will be discussed in detail in the following papers. These include: the instrumentation itself, including probes, and the possible standardization of performance characteristics; reference standards including test blocks and other techniques for setting rejection limits; and finally standarization of application techniques.
Our challenge is first to determine what should be standardized within each area. Then, under what conditions should such standards be applied. The developers of these standards should also clearly understand the complex relationship between the significance of the parameters being standardized, the performance flexibility of the equipment, and the overall cost/benefits involved.
This presentation attempts to put some of these factors into proper perspective, so that realistic standardization may benefit all parties concerned.
Calibration Blocks for Ultrasonic Testing
Authors: Burley CE 
Published: March 2009

The historical development of test blocks is reviewed briefly, leading to the development of the most recent ASTM standards. The large number of test blocks developed by other than ASTM sources is outlined, together with the problems presented by this proliferation of standards.
The current status of ASTM Recommended Practice for Fabricating and Checking Aluminum Ultrasonic Standard Reference Blocks (E 127-75) and ASTM Recommended Practice for Fabrication and Control of Steel Reference Blocks Used in Ultrasonic Inspection (E 428-71(1975)) for flat entry surface standards is discussed, together with the requirements to apply and duplicate the specified calibration procedures.
Current activities of ASTM to improve existing standards are outlined. In conclusion, some requirements for the development of new standards are advanced.
Specification/Code Syndrome
Authors: Plumstead WC 
Published: March 2009

This presentation intends to show a need for fewer standards and specifications from the independent laboratory viewpoint.
Although the independent testing laboratory attempts to maintain an adequate library of specifications, standards, codes, and procedures, it is not uncommon to receive requests to perform tests and evaluate results according to a completely unfamiliar document. New variables introduce a potential for error.
The overall results of liquid penetrant inspection, magnetic particle inspection, and the other nondestructive testing methods would benefit if fewer documents existed which also address the engineering principles behind the testing procedures and acceptance criteria incorporated into the document. Documents of this nature would provide better test performance and more accurate results just as a result of the familiarity created. Personnel training effectiveness would improve with less supervisory control.
Penetrant Inspection Standards
Authors: Packman PF , Hardy G , Malpani JK 
Published: March 2009

The purpose of this paper is to review some of the quantitative techniques that have been used for the evaluation of penetrant systems and to present an analysis technique based on analysis of variance (ANOVA) that appears to have a potential for rating penetrants.
The paper covers five areas: quantitative penetrant methods, two-fold congruency evaluation, the limitations on the reuse of the specimens, the influence of threshold visibility on evaluation of penetrants, and crack line intersection counting and evaluation of the crack line intersection data by ANOVA to evaluate the effects of primary and secondary influencing variables.
Techniques for the Evaluation of Potential Rabbit (Oryctolagus cuniculus) Chemosterilants
Authors: Godfrey ME 
Published: March 2009

Four chemicals shown to be effective as sterilants in other vertebrate species were evaluated for efficacy in the European rabbit (Oryctolagus cuniculus). Weight-related doses were administered, by gavage, to groups of does who were then allowed to form breeding colonies with bucks of proven fertility. Two chemicals were found to have a long-term effect from this single oral dose. Acceptability of these two drugs was evaluated in a no choice situation and found to be adequate. One of these drugs was then used in a simulated field trial where prefeeding prior to exposure to the drugged baits occurred but where alternative feed was also available. The results were inconclusive.
Two chemicals were found to have a long-term effect from a single oral dose, but the duration and variation in effectiveness observed for individual animals indicate that neither drug is suitable for full field use in pest control operations.
Techniques to allow the evaluation of new compounds have been evolved and are applicable to use with other vertebrate pest species as well as the rabbit.
Test Methods for Determining the Efficacy of Coyote Attractants and Repellents
Authors: Linhart SB , Dasch GJ , Roberts JD , Savarie PJ 
Published: March 2009

Methods whereby candidate coyote repellents and attractants can be evaluated are described. Repellents were tested by conditioning wild-caught captive coyotes to feed upon tethered domestic rabbits. Coyotes were then offered treated and untreated rabbits on alternate days for a ten-day period. Efficacy of candidate compounds was based on kill rates. Difficulties associated with field evaluation of repellents are discussed.
Potential coyote attractants were evaluated in the field by recording visitation rates to scent stations. Each scent station consisted of a 3-ft circle of sifted earth in the center of which was placed a capsule containing a candidate attractant. Attractants were alternated between scent stations; animal tracks present at each site were recorded daily until sufficient data were obtained to permit comparisons. Problems that may confound the analysis of attractants by use of captive coyotes are reviewed.
Field Testing a Bird Repellent Chemical on Cereal Crops
Authors: Martin LR , Jackson JJ 
Published: March 2009

Field trials in East Africa with methiocarb (3, 5-dimethyl-4-(methylthio) phenol methylcarbamate) on sorghum, millet, wheat, barley, triticale, and rice indicate that special problems need considerable evaluation before treatment of a cereal crop for protection from bird damage.
Cereals with exposed seeds (sorghum, millet) may need two treatments for extended protection if bird damage begins shortly after flowering. Shielded seeds (wheat, triticale, barley, rice) may need only one treatment depending upon the period of vulnerability, the time at which bird damage begins, and the type of adhesive used. In dry windy climates, a good adhesive is needed. If damage begins after the glumes have begun to dry, an adhesive is essential indicating that early treatment of shielded seeds is the best practice. Milk has been used as a sticker with limited success when commercial adhesives were unavailable. Experiments with many different test plot sizes indicate that areas of approximately 1000 m2 with 2 to 3 m spacing between repetitive plots work well. No single damage assessment technique is suitable for every trial. The assessment method will depend on time and manpower availability and the degree of precision required. A combination of visual and quantitative methods will often yield a more comprehensive assessment than either method alone. Following the evolution of damage and using good bird censusing techniques are essential to determine the necessity of retreatment.
Learned Aversion in Wild Birds: A Method for Testing Comparative Acute Repellency
Authors: Schafer EW , Brunton RB , Lockyer NF 
Published: March 2009

A method was developed to measure the comparative acute learned aversion of a number of wild bird species to repellent chemicals. It was shown that both the innate acute response and the intensity and duration of the learned response of birds to repellents vary among species. Two repellents, methiocarb and thiram, were tested by the described method. Methiocarb produced the stronger and more lasting response in most species; thiram was much more variable in its acute effects, and the intensity and duration of the learned response tended to be weaker and shorter.
Factors relating to improving the test methodology presented are discussed, especially with regard to the species tested.
Prediction of Rail Steel Strength Requirements—A Reliability Approach
Authors: Mair RI , Groenhout R 
Published: March 2009

The determination of rail yield strength levels to support increased wheel loads is usually based on empirical adjustments to the Hertzian equations for contact stresses. A formulation is given, based on reliability theory, which enables a more refined analysis to be carried out and incorporates the material property variations, provided these can be approximated as Gaussian normal distributions.
Application has been made to unit train operations and estimates made of strength levels required for mean wheel loads in excess of 150 kN. The results indicate the importance of rail/wheel tangential forces on rail damage in curves and show that, while variations in wheel loads about the mean have an influence on performance, the effects are not highly significant. Spread of steel strength also has only a marginal influence within the bounds of accepted steelmaking control.
A comparison has been made between the predicted strength level and service trials which indicates that the suggested procedure provides conservative results.
Fatigue and Fracture Behavior of Carbon-Steel Rails
Authors: Barsom JM , Imhof EJ 
Published: March 2009

The Ad Hoc Committee on Rail Research, which is composed of representatives from the American Railway Engineering Association (AREA), the Association of American Railroads (AAR), and the American Iron and Steel Institute (AISI) Committee on Railroad Materials, formulated a program to investigate the effects of metallurgical properties, mechanical properties, and applied stress conditions on the service fracture behavior of carbon-steel rails. This paper presents the fatigue and fracture behavior of five rails having extremes in room-temperature tensile properties and Charpy V-notch toughness, and an analysis of the effect of this behavior on the in-service useful life of carbon-steel rails. These five rails were removed from service after 15 to 18 years of operation and were selected from a population of about 90 rails that were removed from service because they contained service-developed defects. A companion paper in this symposium describes the results of chemical analysis, hardness and tension tests, and the results of wear, deformation, metallographic, and fractographic analysis.
The results of the fractographic investigation conducted under AAR-AISI contract that are presented in part in the companion paper showed that in-service fatigue cracks initiated from inclusions having a width of about 0.03 mm (1.25 mils). The results of the present investigation showed that fatigue crack initiation from such small discontinuities occurs when the magnitude of the stress fluctuations applied to the railhead with the passage of each wheel are equal to about the tensile strength of the steel. The cost of the steelmaking practices required to eliminate such small discontinuities is believed to be economically prohibitive. Moreover, the detection of such discontinuities is beyond the capabilities of presently available nondestructive inspection procedures. The results also showed that the fatigue crack propagation behavior of various carbon-steel rails is essentially identical and is independent of chemical composition or mechanical properties. Moreover, the dynamic fracture toughness of these rails at the minimum operating temperature of about -351°C (-30°F) was about 27.5 MPam(25 ksi in.), and a significant increase in the fracture toughness of the rail would result in a negligible increase in the useful fatigue life of the rail. Significant increase in the fatigue life of rails can be achieved by decreasing the wheel load, by maintaining the roadbed, by changes in the design of rails, and by establishing a residual compressive stress field in the upper portion of the railhead which can be accomplished, for example, by induction hardening. Consequently, it is suggested that the safety and reliability of rails can be ensured best by decreasing the magnitude and fluctuation of the stresses in the rail and by periodic nondestructive inspection of rails.
Preliminary Approaches to Experimental and Numerical Study on Fast Crack Propagation and Crack Arrest
Authors: Kanazawa T , Machida S , Teramoto T 
Published: March 2009

Within the limit of relatively short arrested crack, static approximation by applying linear fracture mechanics has yielded useful results for theoretical interpretation and practical application of currently used brittle fracture propagation arrest test (the concept of arrest toughness). But later experimental investigations using very wide specimens (1300 to 2500-mm-wide plates) have revealed that this simple interpretation fails to have a consistency with the case of a long arrested crack. For the inadequacy of static approximation based on arrest toughness concept, the concept of an effective stress intensity factor has been introduced from a practical point of view without a clear quantitative explanation for it. In search of a more relevant theory for fast crack propagation and to see how the neglect of dynamic aspects affects the interpretation of unstable crack propagation arrest test and philosophy of crack arrest design, a dynamic fracture mechanics analysis was made with the use of the finite-difference method to solve the equation of motion for the two-dimensional elastic problem.
Results of a numerical experiment are presented, and experimental results for polymethylmethacrylate specimen and structural steels are discussed in terms of dynamic fracture mechanics analysis with a focus on energetic aspect of the crack propagation processes.
Computation of Crack Propagation and Arrest by Simulating Microfracturing at the Crack Tip
Authors: Shockey DA , Seaman L , Curran DR 
Published: March 2009

This paper describes the initial development stages of a computational capability for fast fracture and arrest, based on treatment of plastic flow and microfracturing at the crack tip. The approach is to model the events occurring within the process zone, compute the associated energies, and thereby determine the fracture toughnesses of propagating and arresting cracks.
The model treats crack propagation as occurring by the nucleation, growth, and coalescence of microfractures in the plastically deforming material at the crack tip. It uses as input actual measurements from specimens fractured under stress wave loads. The dynamic stress history experienced by this material is calculated by a two-dimensional wave propagation code.
The approach was demonstrated by performing a computational simulation of a Battelle double-cantilever-beam crack arrest experiment and calculating the energies absorbed in plastic flow and microfracturing. Plastic work accounted for about 95 percent of the fracture toughness, but microfracture activity controls the amount of plastic work that is done and hence governs the toughness. Agreement between computed and observed crack velocity and arrest length is not yet satisfactory but should improve when a finer computational grid is used.
The approach offers an avenue for understanding fracture toughness on a micro-level by linking micromechanical material response to continuum toughness parameters.
Effects of Graphite/Epoxy Composite Materials on the Corrosion Behavior of Aircraft Alloys
Authors: Fischer P , DeLuccia JJ 
Published: March 2009

A study was made to evaluate the potential galvanic corrosion problem when graphite-epoxy composite materials are coupled to naval aircraft alloys in the naval air-sea environment. Electrochemical measurements (open circuit potential) showed a relatively large potential difference, approximately 1 V, between the composite and the aluminum alloys 7075-T6, 7075-T651, and 5052-H38. This difference provides the driving force for the corrosion of aluminum as an anode and is cause for concern. Corrosion current data (zero impedance technique) show that these aluminum alloys and cadmium-plated steel are much more reactive than Ti-6A1-4V when coupled to graphite-epoxy (15 versus 0.002 μA/cm2). This technique provides a means of ranking the corrosion problem when graphite-epoxy is coupled to various aircraft alloys.
Flatwise tension test data indicated significant strength losses when graphite-epoxy sandwich specimens, composite facings bonded to aluminum honeycomb, are exposed to salt spray and synthetic seawater plus sulfur dioxide (SO2) spray environments. The strength loss is not entirely due to the galvanic effect.
Data show that galvanic coupling of the composite to 7075-T651 aluminum alloy has no discernible effect on the stress corrosion cracking behavior of the alloy but does increase its general corrosion.
Flexible Rubberized Asphalt Membranes for Inverted Roofing Systems
Authors: Reid WJ 
Published: March 2009

A laboratory test method, based on the “toughness” value of the material, has been developed to distinguish between high- and low-performance rubberized asphalt membranes used in inverted (protected-membrane) roofing systems.
Rubberized asphalts with a high toughness level have been shown, under laboratory conditions, to be capable of bridging structural cracks in concrete decks at temperatures as low as -18°C (0°F). When the temperature is raised, the membrane remains as an undeformed continuous film. On the other hand, membranes with a lower toughness level were shown to fail at high strain rates, while at lower strain rates they sag irreversibly after such a temperature cycle. During application of the membrane, such temperatures may be experienced for short periods of time before the insulation is placed on top of the membrane or before the building is heated.
Field experience in waterproofing applications, including bridge decks, underground parking garages, and plazas as well as roofs, has shown that the toughness level, combined with other properties such as low temperature flexibility, resistance to flow, and penetration, correlate well with actual performance.
Moisture Content in Protected Membrane Roof Insulations—Effect of Design Features
Authors: Hedlin CP 
Published: March 2009

In protected membrane roofs, the thermal insulation is placed above the main waterproof membrane where it is exposed to precipitation. The severity of the wetting problem can be reduced by protective measures.
Fibrous and closed cell plastic insulations, ranging from 150 to 610 mm square and 51 mm thick, were placed on experimental roofs. They were weighed periodically over periods of up to five years.
The results indicate that moisture gains are reduced by increasing deck slope. Sealing the bottom surface significantly reduced moisture gain in a bead polystyrene, but improvement was offset by placing paving stones directly on its upper surface. Slotting the lower insulation surface on a 100-mm-square grid was not found to reduce moisture uptake. Moisture content of some fibrous specimens sealed on the bottom surface and edges remained at less than 4 percent by volume. Others similarly sealed, but with paving stone cover flashed to divert water away from the upper surface, remained at less than 1.5 percent. In most cases, when specimens were placed wet on the roof in winter, significant drying occurred over a period of several months.
Fire Performance of New Roof Covering Materials and Systems and Weathered Asphalt Shingles
Authors: Donahue RL , Castino GT 
Published: March 2009

Fire tests are used to classify built-up and prepared roof covering materials and systems based on their ability to resist the growth and penetration of fires of varying degrees of severity. Spread of flame tests are used to determine the flaming fire growth characteristics on the surface of materials and systems, while intermittent flame and burning wood brand tests measure fire penetration resistance by establishing the capability of a roof covering material or system to protect combustible decking from ignition.
The fire test performances of spray-applied foam systems, asphalt glass mat shingles, and aluminum shingles with various underlayment systems, as well as weathered asphalt organic-felt shingles, a:e examined.
The just mentioned systems and materials perform similarly to the more traditional classified systems.