bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Proposed Criterion for the Oxygen Embrittlement of Zircaloy-4 Fuel Cladding
Authors: Sawatzky A 
Published: March 2009

Under the condition postulated for a loss-of-coolant accident (LOCA), Zircaloy-4 fuel cladding may experience a temperature transient during which it absorbs an appreciable amount of oxygen from the coolant. Theoretical models for predicting cladding behavior during loss-of-coolant (LOC) are being developed, but until the failure mechanisms can be clearly established, an empirical criterion must be employed.
Since, under LOCA conditions, the fuel cladding would be predominantly exposed to tensile hoop stresses, the effects of oxygen on the tensile properties of Zircaloy-4 were investigated. It was found that, from room temperature to 800°C, the tensile properties were essentially independent of maximum cladding temperature and cooling rate, but were dependent on the oxygen distribution through the cladding wall.
On the basis of the present work, but also consistent with other published work, an interim oxygen embrittlement criterion is proposed, which states: “the oxygen concentration must be less than 0.7 weight percent over at least half the cladding thickness.”
Since the proposed criterion requires a prediction of the oxygen distribution for a given temperature transient, the available computer models are briefly described and compared with experiment. Preliminary results suggest that the prediction of OXWEX, SIMTRAN 1, and PRECIP 1 are in reasonable agreement with experiment.
Evaluation Models of Zircaloy Oxidation in Light of Recent Experiments
Authors: Ocken H , Biederman RR , Hann CR , Westerman RE 
Published: March 2009

Measurements of Zircaloy-steam oxidation kinetics on as-received and preoxidized cladding are reported, as are measurements of the inside to outside diameter oxygen ratio following rupture of simulated fuel rods. The kinetics data confirm the conservative nature of the Baker-Just equation and suggest that preoxidation effects would provide an additional element of conservatism in regard to the amount of oxidation that would be expected if a fuel rod were subjected to a pressurized water reactor (PWR)-type temperature transient. Although a great deal of scatter was found in the measured inside-outside diameter oxygen ratios, the average value even at the rupture position was less than unity. The strongest trends showed a decreasing inside-outside diameter oxygen ratio with decreasing test time and increasing distance from the rupture site.
It was found that differences in values of published oxidation kinetics parameters can be reconciled if the procedure used to heat the test specimens is taken into account. A regression analysis of data reported from seven recent investigations showed that the activation energy for the oxidation process was about 7.6 kcal/mole less in experiments using internally heated specimens than in experiments using externally heated specimens. Similar effects are also seen in inside-outside diameter oxygen ratio data; values from externally heated specimens are larger than those from internally heated specimens.
A Monitoring Technique for Assessing Effects of Pollutants on Fish Activity
Authors: Fisher JW , Harrah CB , D'Allessandris R , Collins GT , Muhic LA , Umina JF , Blanchard RE , Klosterman EL 
Published: March 2009

This study describes a method for monitoring the activity of aquatic organisms and reports preliminary results using hydrazine as the pollutant. Activity was detected using strain gages attached to immersed stainless steel paddles. Fish changing position or maintaining their position in the water column created water disturbances, and the relative amount of the water disturbance was used as an index of activity. Analog outputs from the gages were conditioned, amplified, recorded on frequency modulation (FM) magnetic tape, and processed off-line by computer. A computer program was developed that calculated mean absolute voltage levels of combined signals over 1-min intervals.
Preliminary information was obtained in four trials. Fish activity was monitored from 7 a.m. to 2 p.m. with three or four fish per trial. The activity of the control fish and that of the fish exposed to sublethal concentrations of hydrazine were compared by visual inspection of plots of mean 5-min voltage levels. The activity of the exposed fish was inconsistent between trials, variable, and usually not readily distinguishable from the corresponding control fish activity. Nevertheless, this strain gage-paddle apparatus detects fish activity and offers a new technique that has potential as a biological monitor of water and effluent quality.
Comparison of the Toxicities of Biphenyl, Monochlorobiphenyl, and 2,2′,4,4′-Tetrachlorobiphenyl to Fish and Daphnids
Authors: Dill DC , Mayes MA , Mendoza CG , Boggs GU , Emmitte JA 
Published: March 2009

The static acute toxicities of biphenyl, 2-,3-, and 4-monochlorobiphenyl, and 2,2′,4,4′-tetrachlorobiphenyl(2,2′,4,4′-TCB) were determined for three freshwater fish species—bluegill (Lepomis macrochirus Rafinesque), rainbow trout (Salmo gairdneri Richardson) and fathead minnow (Pimephales promelas Rafinesque); one salt-water fish species—sheepshead minnow (Cyprinodon variegatus Lacepede); and one freshwater invertebrate—Daphnia magna Straus. The flow-through toxicities of 2-monochlorobiphenyl (2-MCB) and 2,2′,4,4′-TCB were determined for fathead minnows exposed for up to 32 days.
The static acute test data showed that the toxicities of the monochlorobiphenyls were intermediate between those of biphenyl and 2,2′,4,4′-TCB. There were only slight differences in the static acute median lethal concentrations (LC50S) among the individual monochlorobiphenyl isomers for any one particular species. Daphnids and rainbow trout (Salmo gairdneri) were more sensitive to all the tested compounds than the other species.
The flow-through 30-day LC50 values were 0.82 mg/litre (95 percent confidence interval, 0.73 to 0.94) for 2-MCB, and 0.029 mg/litre (95 percent confidence interval, 0.026 to 0.033) for 2,2′,4,4′-TCB, differing by a factor of 29-fold. In flow-through tests, exposure to both 2-MCB and 2,2′,4,4′-TCB resulted in observable toxic effects within 3 days of exposure. Melanization (body darkening) and loss of equilibrium (swimming disorientation) were the most consistently observed sublethal effects. The Day 3 median effective concentration (EC50) values for melanization were 1.36 mg/litre (95 percent confidence interval, 1.2 to 1.5) and 0.034 mg/litre (95 percent confidence interval, 0.03 to 0.039) for 2-MCB and 2,2′,4,4′-TCB, respectively. The Day 3 EC50 values for loss of equilibrium were 2.11 mg/litre (95 percent confidence interval, 1.93 to 2.37) and 0.054 mg/litre (95 percent confidence interval, 0.045 to 0.065) for 2-MCB and 2,2′,4,4′-TCB, respectively.
A no-observed-effect concentration (the highest concentration of test chemical that killed or affected no greater percentage of test organisms than did the control treatment) was not observed for 2,2′,4,4′-TCB within the range of concentrations set in this test. After 30 days, the fish exposed to the lowest concentration of 2,2′4,4′-TCB (0.014 mg/litre) had stopped feeding, were melanized, and the majority had lost their equilibrium. The two lowest exposure concentrations (0.30 and 0.38 mg/litre) of 2-MCB did not cause mortality or morbidity greater than in the controls. These data indicate that the no-observed-effect concentration for 2-MCB is less than 0.55 mg/litre (the third lowest concentration) and equal to or greater than 0.38 mg/litre.
Steel Cord: Analysis of Used Truck Tires and Simulation of the Found Phenomena in Laboratory Experiments
Authors: de Jong CCJ 
Published: March 2009

Analysis of used tires shows rust formation in the belt by penetration of water, deterioration of the adhesion of steel cord to rubber in the carcass, and also a loss of cord tenacity in the carcass. As a model for the belt, vulcanized T-test adhesion blocks with open cord ends were immersed in warm, salt water (90° C; 5 percent sodium chloride), after which the residual adhesion and rubber coverage were measured. The conclusion is that for a belt material, a good rubber penetration should be sought.
In the carcass the loss of adhesion seems to be the major problem. Thermal aging tests under different aging conditions have been carried out, and a rather large difference between the various products can be observed. Loss of cord tenacity, fretting, apparently is determined by the cord construction. As we have no reliable laboratory testing method available, fleet tests will be decisive in this respect.
Adhesive and Processing Concepts for Tire Reinforcing Materials
Authors: Bhakuni RS , Rye GW , Domchick SJ 
Published: March 2009

A tire can be considered to be a composite of a reinforcing structure material and rubber compound. The reinforcing materials play a major role in tire performance. Several important contributing characteristics of the reinforcing materials are tensile, modulus, dimensional stability, fatigue, and adhesion under tire operating conditions. For optimum tire performance, adequate adhesion between the reinforcing material and the rubber compound is essential.
Choice of adhesive system(s) is dependent upon the nature of the substrates (fiber and rubber) to be bonded, as well as adhesive properties. Conventional resorcinol-formaldehyde-latex adhesion systems provide required adhesion for rayon, nylon, and fiberglass. Polyester and aramid require the use of reactive chemicals.
Time, temperature, and tension variables are required for processing organic fibers to tailor the fiber properties to a specific end use. Fabric properties such as modulus, shrinkage, and fatigue can be modified by varying processing conditions. Heat setting of the adhesive is also obtained during processing. Therefore, it is imperative that processing conditions be selected to achieve optimum fabric properties as well as adequate adhesion.
Processing and adhesive concepts used for organic fibers are reviewed. Effect of energy and environmental factors on the design and operation of the processing units is also discussed.
Study of Fiber Fracture and Interfacial Chemistry Using the Scanning Electron Microscope
Authors: Causa AG 
Published: March 2009

The fracture surfaces of various tire cords (bare or embedded in rubber) were examined using scanning electron microscopy, to identify fractographic features characteristic of certain load history, testing mode, or fiber microstructure.
Axial splitting and fibrillation are the predominant morphological features in the fracture of aramid tire cord under either tensile or cyclic loading. Some additional topographic characteristics are also observed, for example, kink bands under MTS cyclic loading testing and a V-shaped fracture starting at the convex side of the bent fiber in the dynamic flex test.
Under severe dynamic loading, conventional polyester, namely, poly (ethylene terephthalate), shows some splintering, but the splits are much shorter than those noticed in aramid fiber. Under similar testing conditions, an experimental polyester, namely, poly (ethylene-2, 6-naphthalene dicarboxylate) can develop microstructural changes leading to an unusual conchoidal fracture.
The tensile fracture morphology of an experimental P-20 nylon monofil changed with changes in its tensile stress-strain behavior.
Energy dispersive electron microprobe analysis of nylon monofil-rubber interface suggests that sulfur, in the form of a sulfur-zinc complex, has diffused from the rubber phase to the fiber-rubber interface, to react with the adhesive dip.
Bias Passenger Tires: Effect of Construction on the Cord Deformation and Temperature Rise During Rolling
Authors: Prevorsek DC , Beringer CW , Kwon YD , Sharma RK 
Published: March 2009

The effect of carcass construction on the cord deformation and temperature rise in tire during rolling is poorly understood. In order to establish the effects of changes in ply construction, number of plies, crown angle, and cord construction, we analyzed the cord deformation and temperature rise in a set of tires where these carcass construction characteristics were systematically varied. Other tire design variables were maintained constant including the polyethylene terephthalate yarn from which the cords were constructed. Four tires of each type were subjected to (a) an increasing speed-constant load test, and (b) an increasing load-constant speed test which were carried out on a laboratory testing wheel.
By means of an analytical procedure described in detail, we determined the temperature profiles in the tire cross section, the maximum temperature in tire, and the deformation amplitudes of the tire cords. The results of increasing speed and increasing load tests show that the tire which runs coolest at high speeds does not necessarily do so under high loads and vice versa. Cord deformation analysis showed that at high load the cords are subjected to significant compression which is detrimental because the fatigue resistance of polymeric cords in compression is very low. The cords removed from failed section of the tire (sidewall) show distinct kink bands which confirm the results of the deformation analysis.
The Ubiquitous η Factor
Authors: Turner CE 
Published: March 2009

The η factor relates G or J to elastic or plastic work per unit ligament area rather than to the differential of work per unit crack advance. In principle this adds nothing to the understanding of fracture, but in practice it provides convenient relationships for the analysis of several fracture problems. The η factor can be expressed in terms of compliance, load or displacement, instead of work, and can be determined experimentally or analytically. Expressions are given for a selection of elastic, nonlinear, and plastic cases in some of which deep and shallow notch behavior differs markedly.
Application to elastic and plastic test analyses, a J based design curve including an approximate treatment of residual stresses, and both elastic and plastic instability problems are outlined.
Fully Plastic Crack Solutions, Estimation Scheme, and Stability Analyses for the Compact Specimen
Authors: Kumar V , Shih CF 
Published: March 2009

This paper presents the fully plastic solutions for the compact specimen and an estimation scheme that exploits these solutions to generate crack driving force diagrams under contained and large-scale plasticity conditions.
Plane-strain and plane-stress fully plastic solutions for compact specimens are obtained for a wide range of crack length to width ratios and for hardening exponent n of up to 20. The calculations are based on deformation plasticity theory and use the finite element method for incompressible deformation developed by Needleman and Shih. Relevant crack parameters like the J-integral, crack opening displacement, mouth opening displacement, and load-line displacement are appropriately normalized and tabulated. Simple formulas are given for estimating the relevant crack parameters from contained yielding to fully plastic situations using the elastic and the tabulated fully plastic solutions. The results thus obtained are compared with accurate finite element solutions for stationary and extending cracks based on flow theory of plasticity.
Crack driving forces in terms of the J-integral and crack opening displacement are computed for A533B compact specimens using the above estimation scheme. Assuming that the conditions for J-controlled growth are satisfied, the load-displacement behavior, stable crack extension, and the point of instability can be determined from the crack driving force diagrams if the material J-resistance curve is known. Comparisons of the predictions with actual test measurements for several different sized compact specimens show good agreement.
Burst Criterion of Zircaloy Fuel Claddings in a Loss-of-Coolant Accident
Authors: Erbacher FJ , Neitzel HJ , Rosinger H , Schmidt H , Wiehr K 
Published: March 2009

A burst criterion model has been developed to calculate the burst data of Zircaloy claddings of a pressurized water reactor in a loss-of-coolant accident. It is assumed by this model that the time of burst is reached when the local stress equals the limiting burst stress. The burst stress is assumed to depend on the temperature and oxygen concentration of the Zircaloy.
With the histories of temperature and pressure known, the strain, stress, and oxygen content can be calculated by integration of the creep equation and correlation of the oxidation kinetics. Once the time of burst has been calculated, all burst data, that is, strain, stress, temperature, pressure, and oxygen content, are determined.
To verify the burst criterion model, single-rod transient burst tests in steam were performed using fuel rod simulators with indirect electric heating. The test parameters covered the following ranges: internal overpressure—10 to 140 bar, heating rate—1 to 30 K/s.
The burst temperatures and burst strains predicted by the burst criterion model are in good agreement with the test data.
Stress Corrosion Cracking Test with Slow Strain Rate and Constant Current
Authors: Ondrejcin RS 
Published: March 2009

A rapid electrochemical tension test was developed for evaluating stress corrosion crack initiation in carbon steel. Constant anodic current was imposed on smooth-bar tension specimens as the specimens were slowly strained to fracture at 1.3 × 10-6/s. Equivalent results were obtained for the following ductility properties measured: uniform elongation, total elongation, and reduction of area. Total elongation was chosen as the index for stress corrosion crack initiation. An equation was developed that allowed calculation of total elongation of specimens in electrolytes (test solutions) with composition ranges of 1.5 to 5.5 M nitrate, 0 to 3.5 M nitrite, and 0 to 5.0 M hydroxide, and a temperature range of 50 to 100°C. A minimum of 13 percent total elongation was selected to indicate the possible initiation of cracking in A 285-B steel alloy.
The test was used to evaluate relative aggressiveness of synthetic nuclear wastes on A 285-B carbon steel and the relative resistances of several steels to given solution compositions. Test results formed one of the bases for setting temperature and concentration limits for several ions in nuclear wastes that are stored in carbon steel tanks at the Savannah River Plant.
Application of the 14C Organic Mineralization Technique to Marine Sediments
Authors: Litchfield CD , Devanas MA , Zindulis J , Carty CE , Nakas JP , Martin EL 
Published: March 2009

This research was designed to demonstrate the usefulness of the heterotrophic mineralization technique in marine sediments and to assess the temporal and spatial heterogeneity of the marine sedimentary microbial population. To do this, adaptation of the mineralization procedures using [14C]urea and [U-14C]-L-aspartic acid was made. Exact details outlining procedures, replicates, substrate concentration, incubation conditions, etc. are described. The turnover times and maximal uptake velocity (Vmax) of substrate utilization as well as the total colony-forming units (CFU) on various media were all calculated according to standard procedures.
Temporal heterogeneity was examined during two cruises in August 1975 and August 1976 by repeated sampling at one or more stations during a 24- to 48-h cycle. From the measured parameters, there appears to be no significant diel periodicity in either the level of microbial activity or in the CFU. Calculated values for turnover times generally showed less variation than did the values for maximal uptake velocities.
Spatial heterogeneity in the sediments was evaluated using a multiple corer, which took four cores within 1 m2. Although slight variations in the absolute activity levels do exist within a station, they do not appear to be significant at the p = 0.1 level. Interstation variability is significant at p = 0.1. At the continuously reoccupied station, August 1975, close correlation between the numbers of CFU on selective media and the utilization of that 14C-labeled substrate indicated that the technique is indeed measuring microbial activity. Therefore, it is possible to use the 14C heterotrophic mineralizaion method in marine sediments, provided replication and sufficient controls are included. Within a designated station, the rather large sample size required obscures any microheterogeneity and provides an index of the level of microbial heterotrophic activity.
Effects of Metallurgical and Mechanical Factors on Charpy Impact Toughness of Extra-Low Interstitial Ferritic Stainless Steels
Authors: Ohashi N , Ono Y , Kinoshita N , Yoshioka K 
Published: March 2009

The effects of precipitates, grain size, plate thickness, and notch sharpness on the Charpy impact toughness of extra-low interstitial 18Cr-2Mo, 26Cr-1Mo, and 29Cr-2Mo steels were investigated.
The steels exhibit good toughness in the solution-treated condition at 1000 to 1200°C and subsequently in the 2-mm V-notched condition. If the steels are subjected to fatigue cracks or brittle weld cracks, their transition temperatures increase and their shelf energies decrease.
When the steels are slowly cooled from the solution temperatures or reheated at intermediate temperatures, 700 to 900°C, after solution treatments, precipitation of second phases occurs, such as Laves phase in 18Cr-2Mo steel and sigma phase in 26Cr-1Mo and 29Cr-2Mo steels. The steels are embrittled by these precipitates and behave very similarly to the solution-treated specimens, having sharp notches such as fatigue cracks or brittle weld cracks.
A decrease in grain size or thickness is beneficial in lowering the transition temperatures of solution-treated and 2-mm V-notched specimens. This effect, however, decreases, when the specimens have brittle weld cracks.
These test results suggest that the solution-treated steels have good resistance to brittle fracture initiation and poor resistance to brittle crack propagation. Precipitation of second phases assists mainly crack initiation but also crack propagation to a lesser extent.
Residual Elements Have Significant Effects on the Elevated-Temperature Properties of Austenitic Stainless Steel Welds
Authors: Edmonds DP , King RT , Goodwin GM 
Published: March 2009

The influence of various residual elements on the elevated-temperature properties of austenitic stainless steel welds has been investigated at the Oak Ridge National Laboratory (ORNL). Included in this investigation are the effects of boron, phosphorus, titanium, carbon, sulfur, and silicon. This work is aimed at developing austenitic stainless steel weld materials with enhanced elevated-temperature properties.
The materials investigated include types 308, 316, and 16-8-2 stainless steel weld metals. Processes investigated include shielded metal-arc (SMA), gas tungsten-arc (GTA), and submerged-arc (SA) welding. Early work was done with Types 308 and 316 SMA weld metals, where the greatest enhancement of properties resulted from controlled additions of boron, phosphorus, and titanium to the deposits. Significant improvements in the properties of GTA and SA welds also result from the addition of these residual elements. The optimum residual element compositions were determined to be nominally 0.05Ti-0.04P-0.006B for SMA welds and 0.5Ti-0.04P-0.006B for GTA welds. Submerged-arc welds with 0.2Ti have exhibited improved creep strengths for all three materials.