bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microstructural Aspects of the Fracture Toughness Cleavage-Fibrous Transition for Reactor-Grade Steel
Authors: Ogawa K , Zhang XJ , Kobayashi T , Armstrong RW , Irwin GR 
Published: December 2008

Particularly in the transition temperature range, reliable use of toughness data, from small specimens of structural steel can be helped by improved understanding of the initiation of cleavage. For this purpose, fracture details in local regions were studied. Methods of examination were scanning electron microscopic (SEM) fractography, microstructural analysis, hardness tests, and topographic examination of fracture surfaces.
The results indicate that examination of fracture surface morphology through SEM fractography is essential for improved understanding of cleavage fracturing in the transition range. Fracture surface details reflect influences of both ferrite and prior-austenite grain size. In addition, for some specimens, fracture morphology is also influenced by a large size inhomogeneity due to dendritic solidification. In heavy section A533B steel, explanations for large scatter of small specimen KIc estimates may be closely related to dendritic inhomogeneity.
Assessment of Hazardous Waste Management Practices for Potential Damage to the Environment in EPA Region III
Authors: Gillen BD , Tusa WK 
Published: December 2008

This paper evaluates damage case histories associated with land-based and non-land-based hazardous waste facilities in U.S. Environmental Protection Agency (EPA) Region III. This information was extrapolated from a nationwide study authorized by the EPA Office of Solid Waste. It provides an outline of the kinds of environmental damage associated with certain types of facilities and contamination events and measures the overall extent and damage resulting from mismanagement of hazardous wastes in the region.
Approximately 93% of the sites evaluated had evidence of suspected or documented contamination. Damage loss was suspected or documented at 73% of the sites involving contamination, with 38% of the sites evaluated having documented evidence of damage to human health or the environment. The data compiled in this study were used with similar information compiled from the other EPA regions, as part of the agency's ongoing Regulatory Impact Analysis (RIA) program and for use in preparing regulations tailored for specific facility types.
A Review of Chevron-Notched Fracture Specimens
Authors: Newman JC 
Published: December 2008

This paper reviews the historical development of chevron-notched fracture specimens; it also compares stress-intensity factors and load line displacement solutions that have been proposed for some of these specimens. The review covers the original bend-bar configurations up to the present day short-rod and bar specimens. In particular, the results of a recent analytical round robin that was conducted by an ASTM Task Group on Chevron-Notched Specimens are presented.
In the round robin, three institutions calculated stress-intensity factors for either the chevron-notched round-rod or square-bar specimens. These analytical solutions were compared among themselves, and then among the various experimental solutions that have been proposed for these specimens. The experimental and analytical stress-intensity factor solutions that were obtained from the compliance method agreed within 3% for both specimens. An assessment of the consensus stress-intensity factor (compliance) solution for these specimens is made.
The stress-intensity factor solutions proposed for three- and four-point bend chevron-notched specimens are also reviewed. On the basis of this review, the bend-bar configurations need further experimental and analytical calibrations.
The chevron-notched rod, bar, and bend-bar specimens were developed to determine fracture toughness of brittle materials, materials that exhibit flat or nearly flat crack-growth resistance curves. The problems associated with using such specimens for materials that have a rising crack-growth resistance curve are reviewed.
Effect of Low Temperature on Fatigue and Fracture Properties of Ti-5Al-2.5Sn(ELI) for Use in Engine Components
Authors: Ryder JT , Witzell WE 
Published: December 2008

The results of an experimental investigation designed to obtain the material property data necessary to establish the salient characteristics of a Ti-5Al-2.5Sn(ELI) alloy for use in a fuel pump impellor at cryogenic temperatures are described. Tension, fracture toughness, and fatigue crack propagation data were obtained from pancake forgings at room temperature in laboratory air and at 20 K (−423°F) in liquid hydrogen. Experiments were performed on coupons of three different orientations, from different forgings, and from different forging lots. The effect of frequency (0.1 and 10 Hz) and R ratio (+0.05 and +0.5) on crack propagation was evaluated.
Tensile strength significantly increased at cryogenic temperatures compared to room temperature, percent elongation had a minor reduction, percent reduction in area significantly decreased, and modulus increased approximately 8%. Fracture toughness showed a significant reduction at cryogenic temperatures, as expected. A difference in toughness caused by orientation of as much as 25% was observed, despite the lack of any significant differences in material texture. The fatigue crack growth rate of this alloy showed a remarkable lack of sensitivity to the various experimental conditions. Crack orientation effects were minimal, although there were some small shifts in threshold. The two different forging lots resulted in a small shift in growth rate. No effect of frequency was found at any combination of R ratio and temperature. A load ratio effect was observed, but this expected result was manifested only by a small shift to higher rates at R = 0.5. No effect of temperature on fatigue crack propagation was observed from threshold (∼10−8 m/cycle [∼4 × 10−7 in./cycle]) to 44 MPa √m (40 ksi √in.) (∼1 × 10−6 m/cycle [∼4 × 10−5 in./cycle]). Above this level the observed difference in growth rate was due to the lower fracture toughness at 20 K (−423°F).
Correcting Flexible Pavement Deficiencies: The Ontario Way
Authors: Chong GJ , Phang WA 
Published: December 2008

Ontario emphasizes preservation of their highway system by carrying out maintenance activities aimed at prolonging the life of highway pavements. To make the maintenance task easier and more effective, a set of guidelines was developed that helps maintenance staff make the best decision, one that is most cost-effective and one that is made consistently by different maintenance staff. For the most part, the guidelines deal with short-term measures-deficiencies that have to be fixed right now, that is, corrective maintenance. But they can also be used to identify situations where preventive maintenance will affect the service life of the pavement. The guidelines contain the following elements: (1) identification process, (2) treatment selection, and (3) performance standard.
This paper describes our current practice of identifying and classifying a typical deficiency, selection of the most cost-effective treatment, the specifications for equipment and materials needed to carry out the treatment, and the proper work methods. As a typical example, this paper will describe flexible pavement crackings and cracks that are routed and sealed as the prescribed treatment.
Time/Toxicity Relationships in Short-Term Static, Dynamic, and Plug-Flow Bioassays
Authors: Bailey HC , Liu DHW , Javitz HA 
Published: December 2008

In order to determine the efficacy of using data from 96-h acute bioassays for predicting toxicity associated with shorter exposure periods, a series of static, dynamic, and plug-flow bioassays were performed using bluegill as test organisms. Test chemicals included acrylonitrile, ammonia, chlorobenzene, chromic acid, copper sulfate, 2-ethoxyethylacetate, methylmethacrylate, sodium hydroxide, sulfuric acid, and xylene. Exposure durations ranged from 1 to 96 h. Regression techniques were used to develop time-toxicity curves to determine how well short-term toxicity could be predicted by 24 to 96 h data.The results from these experiments indicate that data from 24 to 96-h exposure periods have limited use in predicting toxicity associated with shorter exposure periods, depending on the desired level of precision of the estimate. In extreme cases, the estimated LC50s ranged from twenty-fold below to three-fold above the observed LC50 values. In most cases, however, agreement between the estimated and actual LC50 values was much closer. While the usefulness of such mathematical predictors remains to be established, they could have merit in assessing the potential toxicity associated with single-event exposures such as chemical spills or runoff events.
The Acute Toxicity of Chlorine on Freshwater Organisms: Time-Concentration Relationships of Constant and Intermittent Exposures
Authors: Wang MP , Hanson SA 
Published: December 2008

The effect of chlorine exposures on the survival of freshwater aquatic life is of major concern within many of the waterbodies in the United States. Continuous chlorine exposures are a typical result of effluent releases from wastewater treatment plants. Intermittent chlorine exposures are representative of the “blow down” antifouling procedure used for cooling towers in power plants.
The purpose of this paper is to present the derivation and resulting mathematical expressions for the time-concentration relationship of chlorine exposure and survival of freshwater aquatic organisms. Two topics will be discussed: the time-concentration toxicity relationship for constant chlorine exposures and the prediction from the constant exposure mathematical expressions of toxicity caused by intermittent exposures.
An extensive literature review provided the database from which mathematical time-concentration relationships were derived for constant chlorine exposures. Relationships were analyzed for individual species. The resistance of all the different species increased significantly from a 96-h exposure period to an 8-h exposure period.
The intermittent chlorine exposure tests differ not only in the frequency and duration of the chlorine dose but also in the geometric form of the dose application. A kinetic model, which accounted for these variabilities, was used to predict intermittent exposure mortality. The parameters of the model were obtained from the analysis of constant exposure results. In addition to predicting mortality resulting from variable exposure patterns, the kinetic model may be used to design appropriate test durations for intermittent chlorination experiments.
An Aquatic Hazard Assessment: Picloram
Authors: Mayes MA , Oliver GR 
Published: December 2008

Picloram (4-amino-3,5,6-trichloropicolinic acid) exhibits herbicidal activities on broadleaf weeds and woody plants and is registered under the trademarks of TORDON®, GRAZON®, and AMDON® herbicides. It is an organic acid (pKa = 3.2); thus at environmental pH ranges it is usually found in the ionized anionic form. Other physicochemical characteristics of picloram are water solubility 430 mg/L and vapor pressure 6.16 × 10−7 mm mercury at 35°C. The rate of dissipation of picloram in soil is dependent on the application rate, soil type, and climate. Picloram is classified as having moderate mobility in soil; however, the runoff potential of picloram is normally limited to less than 5% of the applied chemical removed from the site in runoff waters.Picloram is relatively nontoxic to freshwater fishes, with acute LC50 values for technical acid ranging from 4.3 mg/L for lake trout [Salvelinus namaycush (Walbaum)] to 55.3 mg/L for fathead minnows (Pimephales promelas Rafinesque). Freshwater invertebrates show similar susceptibility to technical picloram with acute LC50 values ranging from 27 mg/L for Gammarus lacustris Sars to 68.3 mg/L for Daphnia magna Straus. The most sensitive marine invertebrate tested is the eastern oyster [Crassostrea virginica (Gmelin)] with 18 &lt; EC50 &lt; 32 mg/L when exposed to a potassium salt formulation of picloram. Because of its relatively low toxicity to aquatic organisms and low potential for substantial quantities to enter the aquatic environment, picloram is not expected to present a hazard to the aquatic environment.
A Method to Avoid Crevice Corrosion in Electrochemical Determination of Pitting Potentials
Authors: Hakkarainen T 
Published: December 2008

A test arrangement is described, where the electrolyte is brought into contact with the test surface along a multilayered textile tape. This method brings several advantages when compared to the common specimen holders, where part of the specimen surface is masked off by some insulating material. In the absence of crevices, there is no crevice corrosion. No special pretreatment of the test surface is required. Thus, various surface conditions can be tested, including as-received surfaces. The test surface need not be planar. Specimens like bars or weld beads can easily be tested. The desired surface can be selected for the test. The spatial orientation of the test surface can be chosen deliberately. The shape and size of the specimen can vary greatly, which makes the specimen preparation in most cases extremely easy.
The possible uses of the method are demonstrated by room temperature testing of stainless steel sheets and welds in sodium chloride solutions, as well as testing of prestressing steel wire in a saturated calcium hydroxide solution with various concentrations of sodium chloride. Both pit nucleation and repassivation potentials are determined using potentiokinetic techniques. The effects of some experimental variables are studied and discussed.
The Influence of Both Major and Minor Element Composition on Void Swelling in Austenitic Steels
Authors: Garner FA , Kumar AS 
Published: December 2008

Data on the neutron-induced swelling of simple Fe-Ni-Cr austenitic alloys are presented to show that there are three compositional regimes of swelling as a function of nickel content. The intermediate transition regime can be shifted to higher or lower nickel levels as a function of chromium content, various solutes, displacement rate, temperature, and helium level. Such shifts can preclude the observation of either the lower or upper nickel regime. The lower nickel regime is also obscured in ion bombardment studies because of factors that are atypical of the neutron environment.
Data are also presented to show the influence of silicon and phosphorus on the neutron-induced swelling of Fe-25Ni-15Cr and to demonstrate that the separate influence of each of these elements is more complex than previously observed. Similar complex trends have also been seen in ion bombardment experiments, but there are additional distortions relative to the neutron-induced behavior that arise from the interaction of these elements with point defect gradients.
A model is presented to show that the major effect of composition on swelling lies in its influence on void nucleation, operating primarily on the intermediate transition regime. Compositional variations thus appear as a “temperature shift” analogous to that associated with changes in displacement rate. This shift is due to the effect of each element on the vacancy supersaturation via their effect on either the equilibrium vacancy concentration or the effective vacancy diffusion coefficient.
Maturity Functions for Concrete Cured During Winter Conditions
Authors: Naik TR 
Published: December 2008

The objective of this paper is to check the validity of the Nurse-Saul and the Arrhenius maturity functions for concrete cured under winter conditions.
The test specimens used for concrete compressive strength determination were 101.6 by 203.2-mm (4 by 8-in.) cylinders. (The measurements were made in English units.) These specimens were cured at nominal temperatures of 2.8, 12.8, and 22.8°C (37, 55, and 73°F). The cylinders were cast from concrete with water-to-cement ratios of 0.50, 0.60, and 0.70. Tests for compressive strength were performed at the ages of 12, 18, 24, 36, 48, 72, 120 (five days), and 168 h (seven days). The maturity and temperature of the cylinders were recorded at each test age. Curves were plotted for the compressive strength versus the relative maturity at 20°C for each water-to-cement ratio and for different curing temperatures. It was determined that the Arrhenius function gives better correlation between the relative maturity and the strength than the Nurse-Saul function. The author concludes that the Nurse-Saul function should not be used for maturity-strength determination under winter curing conditions.
Three-Dimensional Elastic-Plastic Finite Element Analysis of Three-Point Bend Specimens
Authors: Wellman GW , Rolfe ST , Dodds RH 
Published: December 2008

Elastic-plastic finite element analyses of the three-point bend specimen geometry were performed as part of an investigation to study the application of the crack tip opening displacement (CTOD) fracture parameter to flawed pressure vessels. The elastic-plastic fracture mechanics (EPFM) parameters, CTOD and J, were determined from the results of two- and three-dimensional finite element analyses. Three sizes of the preferred specimen geometry (thickness, t, by depth, 2t, by span, 8t) and five steels with varying stress-strain characteristics were considered. To obtain experimental results for comparison, tests were conducted in accordance with the procedure outlined in British Standard BS 5762:1979, “Methods for Crack Opening Displacement Testing.”
Analytical CTOD values were determined from the finite element nodal displacements using the 90-deg intercept procedure proposed by Rice. Semi-empirical CTOD values were computed by applying the formula in BS 5762:1979 to the computed clip-gage displacements. The finite element analyses were demonstrated to yield CTOD values consistent with the experimental values for the three-point bend specimen. This represents the first step in verifying use of the finite element method to predict applied CTOD values in more complex structures.
The J-integral was determined from two-dimensional finite element results using direct contour integration. The J-integral values were used in conjunction with the corresponding CTOD values to develop an improved correlation between J and CTOD for a wide range of material characteristics.
The paper concludes with a discussion of “level of performance” for the three-point bend specimen. The level of performance is characterized by the value of CTOD at various sizes of the plastic zone as a function of specimen size and material. Three levels of performance are identified: (1) KIc as defined by ASTM Test for Plane-Strain Fracture Toughness of Metallic Materials (E 399), (2) development of a plastic hinge, and (3) initiation of ductile fibrous tearing. An understanding of these levels of performance and their relation to values of CTOD is essential in developing realistic requirements for material toughness.
Extractive Metallurgy of Zirconium—1945 to the Present
Authors: Stephens WW 
Published: December 2008

Although the history of the reduction of zirconium dates from 1824 and the first ductile zirconium metal was produced in the laboratory in 1914, modern reduction practice was pioneered by the U.S. Bureau of Mines starting in 1945.
This paper reviews the history of the extractive metallurgy of zirconium from the early work of W. J. Kroll and co-workers at the Bureau of Mines in Albany. Ore., through the commercial development of the production of reactor-grade zirconium metal which was spurred by the requirements of the Naval Reactor Program and the development of commercial nuclear power.
Technical subjects covered include processes for opening the ore, zirconium-hafnium separation, chlorination of zirconium oxide, reduction processes, and electro-winning of zirconium metal. Proposed new processes and process modifications are reviewed.
Irradiation Creep and Growth During Proton and Neutron Bombardment of Zircaloy-2 Plate
Authors: Chapman OJV , McElroy RJ , Sheldon BE 
Published: December 2008

Proton irradiation creep and in-pile creep and growth tests have been conducted on specimens cut from the same rolled and annealed Zircaloy-2 plate. The proton irradiation creep tests were carried out over the following ranges: stress, 0 to 267 MPa; damage rate, 0.15 to 7.0 × 10−7 dpa/s; temperature, 513 to 613 K; and dose, up to 1.44 dpa.
These data were analyzed in detail on the basis of single variable tests to give a phenomenological equation of the form ˙ϵϒ=˙G+Aσnφmexp(−¯QRTq) where ˙ϵT = total strain rate, ˙G = growth rate, σ = applied stress, φ = damage rate, = growth rate, σ = applied stress, φ = damage rate, T = temperature, and A, n, m, Q, R, and q = material parameters.
Over the range studied the stress and damage rate exponents were unity and the temperature dependence was best described with a q-value of 0.5. Longitudinal and transverse specimens exhibited a degree of creep anisotropy.
Additional specimens were reactor preirradiated to a dose of 1.0 dpa and tested in the ion accelerator. The results of these tests were in excellent agreement with the equation.
The in-pile tests were carried out at the following values: stress, 80 and 140 MPa; damage rate, 9.7 × 10−8 dpa/s; temperature, 543 to 593 K; and dose, up to 1.42 dpa. These tests also gave results that were in good agreement with the prediction of the equation.
Effect of Bundle Size on Cladding Deformation in LOCA Simulation Tests
Authors: Chapman RH , Crowley JL , Longest AW 
Published: December 2008

Two loss-of-coolant accident (LOCA) simulation tests were conducted to investigate the effects of temperature uniformity and radial restraint boundary conditions on Zircaloy cladding deformation with a very low flow of superheated steam. In one test (B-5), boundary conditions typical of a large array were imposed on an inner 4-by-4 square array by two concentric rings of interacting guard fuel pin simulators. In the other test (B-3), the boundary conditions were imposed on a 4-by-4 square array by a noninteracting heated shroud. Test parameters conductive to large deformation were selected to favor rod-to-rod interactions.The tests showed that rod-to-rod interactions play an important role in the deformation process. While burst temperatures and burst strains were not affected appreciably, the interactions in the large array significantly influenced the deformation patterns and caused greater volumetric expansion of the interior simulators. Volumetric expansion of the simulators in the small array was significantly less than that for the central array of the large test; burst strains were approximately the same. Burst temperature-pressure data for the small array and for the outer ring of simulators in the large array agreed with predictions based on single-rod heated shroud tests. All the B-5 simulators burst at approximately the same temperature; however, the interior simulators burst generally at much lower pressures than the exterior ones, and their performance did not agree as well with the prediction.It was concluded that, for conditions conductive to large deformation, at least two concentric rings of deforming guard simulators are necessary to model radial temperature and mechanical boundary effects of large arrays in LOCA simulation tests and that flow area restriction may be underestimated by small unconstrained bundle tests.