bluuebunny/crossref_metadata_2025_split huggingface dataset:
Column Leach Testing of Phenol and Trichloroethylene Stabilized/Solidified with Portland Cement
Authors: Kolvites B , Bishop P 
Published: December 2008

The ability of portland cement to stabilize/solidify organic wastes was evaluated by conducting column leaching tests on portland cement pastes containing phenol and trich loroethylene (TCE). Synthetic solidified waste was manufactured by mixing dilute aqueous solutions of phenol and TCE with Portland Type II cement at a 0.5 liquid-to-cement ratio. The liquid consisted of either 4000 mg/L phenol or 1100 mg/L TCE in purified water. The cement was cured for 3 days and 28 days at 100% humidity at room temperature. Thirty grams of particles approximately 5 to 10 mm in diameter were placed in an enclosed leaching ap paratus. Purified water was pumped upward through the column at a rate of 0.08 to 0.18 mL/ min. Every 48 h for eight days, samples of the leachate in the collection flask and samples of the vapor in the head spaces above the collection flask and leaching column were analyzed by gas chromatography. The concentrations of phenol and TCE found in these samples were used to calculate the total mass of the organic compound which was released from the solidified waste during eight days of leaching.
An empirical mathematical model was used to predict the long-term leaching characteristics of the stabilized phenol waste. The leachability indexes calculated for phenol in cement paste cured 3 days and 28 days were 7.7 and 8.2, respectively. This index rates the relative mobility of the contaminant on a uniform scale that varies from 5 (very mobile) to 15 (immobile). Similar leachability indexes could not be calculated for cement paste containing TCE due to unquantified losses of TCE by volatilization prior to the start of the leach tests and suspected decomposition of TCE in the highly alkaline environment. Gas chromatograms of the TCE waste leachates contained unidentified peaks which were thought to represent the products of TCE decomposition.
Solubility and Stability of Inorganic Iodides: Candidate Waste Forms for Iodine-129
Authors: Taylor P , Lopata VJ , Wood DD , Yacyshyn H 
Published: December 2008

Iodine-129 and carbon-14 are of lesser importance than many other radionuclides in nuclear waste management because of their relatively low radiotoxicity. Their safe immobilization and disposal, however, is a significant challenge because their chemical properties are quite different from most other components of nuclear fuel waste. The authors have sought thermodynamically defensible inorganic waste forms for both of these radioisotopes.This paper discusses the stability and solubility of inorganic iodides as they relate to the selection of a waste form for iodine-129. The best candidates appear to be silver iodide (AgI), either alone or in combination with silver chloride (AgCl), and a combination of Bi5O7I and Bi2O3. Neither is completely satisfactory. The principal drawback of AgI is its relative ease of reduction. High chloride concentrations also increase the solubility of Agl, but it is insensitive to carbonate. The main disadvantage of bismuth oxyiodide is its susceptibility to displacement reactions with dissolved chloride and carbonate; also, it is unstable under strongly reducing conditions.
Stabilization of Mixed Waste at the Idaho National Engineering Laboratory
Authors: Boehmer AM , Gillins RL , Larsen MM 
Published: December 2008

EG&G Idaho, Inc. has initiated a program to develop safe, efficient, cost-effective treatment methods for the stabilization of some of the hazardous and mixed wastes generated at the Idaho National Engineering Laboratory. Laboratory-scale testing has shown that Extraction Procedure toxic wastes can be successfully stabilized by solidification, using various binders to produce nontoxic, stable waste forms for safe, long-term disposal as either landfill waste or low-level radioactive waste, depending upon the radioactivity content.
This paper presents the results of drum-scale solidification testing conducted on hazardous, low-level incinerator fly ash generated at the Waste Experimental Reduction Facility. The drum-scale test program was conducted to verify that laboratory-scale results could be successfully adapted into a production operation.
The Effect of Rules and Officiating on the Occurrence and Prevention of Injuries
Authors: Parayre R 
Published: December 2008

From past and present experiences in Canadian hockey, there seems to be a definite link between the rules of the game and their application (or lack thereof) and the potential for injuries of any type as a result of playing the sport.
Most people feel, rightly or wrongly, that the focal point of our sport with regard to injury incidence and prevention is officiating. The major roadblock which has confronted various hockey constituents, and which is still very much present to this day, is a variety of attitudes towards the way a game should be played. For the official as well as for the administrator, the task often becomes difficult, as they both have to deal with a wide gamut of attitudes towards the sport and try to maintain order and harmony among players, coaches, team and league executives, fans, the media, and the general public.
Clear progress was evident with the advent of facial protection. However, it seems that this positive step has brought on a false sense of security on the players' part and a permissive attitude on the part of officials (among others). The ensuing spinal injuries have recently forced the Canadian Amateur Hockey Association (CAHA) to toughen up rules on checking from behind and to initiate a national movement to cut down on stick infractions. At the present time, we seem to be going in the right direction. The key to success, the CAHA has found, is public awareness and education. Specifically, it recognizes the necessity for the officials to enforce the rules as intended, thereby putting the onus on the coaches, the players, and several other game constituents to adjust their attitudes and habits accordingly.
Performance of a Thin-Surfaced, Crushed-Stone Base Pavement
Authors: Barksdale RD , Greene RL , Bush AJ , Machemehl CA 
Published: December 2008

An experimental pavement approximately 200 m (650 ft) long was constructed in May of 1978 consisting of a 19-mm (0.75-in.) triple surface treatment over a 460-mm (18 in.) crushed-stone base. By 1985 the pavement had been subjected to about 1.4 million equivalent 80 kN (18 kip) American Association of State Highway and Transportation Officials (AASHTO) single-axle loads neglecting front axle effects. The straight segment of the pavement had a present serviceability rating of 3.0 to 3.5 in 1985. About 6.5% surface cracking had developed mostly within the last two years (1984 to 1985). The pavement is constructed on a clayey and sandy silt subgrade which is relatively dry and has a field California bearing ratio (CBR) of 10. The crushed stone base is well graded, has a maximum aggregate size of 30 mm (1.5 in.), and contains less than 2.0% fines. Field tests performed on the pavement included static plate load tests, Benkelman beam, surface strain measurements, and falling weight deflectometer (FWD) tests.
Using the AASHTO design method, a base course layer coefficient for the upper 305 mm (12 in.) was backcalculated to be 0.18, and 0.16 for the remaining stone base. The elastic modulus of the base was backfigured from the FWD test results to be 406 MN/m2 (59 ksi) using the Waterways Experiment Station (WES) approach; other methods of backcalculation gave widely varying results. The elastic moduli of the base and subgrade depend upon the test method and also the mean stress and shearing strain to which the material is subjected. Because of the difference in loading conditions, the elastic modulus of the base will be somewhat lower under a dual-wheel, 80-kN (18-kip) axle loading than under the single, 40-kN (9-kip) FWD test loading.
Prediction of Permanent Deformation in Flexible Pavement Materials
Authors: Tseng K-H , Lytton RL 
Published: December 2008

This paper presents a method to predict the permanent deformation (rutting) in pavements using a mechanistic-empirical model of material characterization. Three permanent deformation parameters are developed through material testing to simply represent the curved relationship between permanent strains and the number of load cycles. Equations are developed by regression analysis which determine how these three parameters are affected by the material properties, environmental conditions (moisture and temperature), and stress state. These relations are important in calculating the permanent deformation of pavement layers since the relation between permanent deformation and cycles of load from the laboratory is usually examined in test conditions that are significantly different from field conditions. The permanent deformations calculated from the method presented are compared with results measured in the field in Florida and are found to be accurate.
The permanent deformation is calculated as the sum of the resilient strains multiplied by the fractional increase of total strains for each material layer of the pavement. The resilient strains of pavement structures under highway loadings are calculated using a finite-element analysis which incorporates both linear and nonlinear stress-strain behavior of the pavement component materials. The fractional increase of total strains is basically in terms of three parameters which characterize the permanent deformation relations from the laboratory. The values of these parameters are developed for pavement materials such as asphalt concrete, gravel and crushed-stone base course materials, and subgrade soils from a variety of data sources. The statistical equations for the three parameters are developed for each type of material represented in the data. The most important terms in the equations are the asphalt content, temperature, resilient modulus, and stress state for asphalt concrete material, and the water content, resilient modulus, and stress state for base and subgrade soils, respectively. These equations and the method as mentioned above has been programmed into a modified ILLI-PAVE program to calculate the resilient strains and permanent deformation in each layer of pavement, taking into account realistic distributions of tire contact pressures, both vertical and horizontal.
The permanent deformation obtained is shown to be in reasonable agreement with the measured results. It is demonstrated that this method provides an appropriate and realistic analysis of prediction of the permanent deformation, and further, the results are used in the prediction of the loss of serviceability index of pavements using the American Association of State Highway and Transportation Officials (AASHTO) Road Test relation. The paper demonstrates the importance of accurate materials characterization in predicting the rutting of asphalt concrete pavements on granular base course.
Resin Impregnation During the Manufacture of Thermoplastic Matrix Composite Materials
Authors: Coulter JP , Güçeri SI 
Published: December 2008

A numerical investigation was performed into the resin flow that occurs during the manufacture of thermoplastic matrix composite materials. Specific attention was directed towards modeling the fiber/matrix consolidation that occurs during resin film stacking/compression molding processes. The understanding of these processes is important to the field of composite materials because it is desirable to know the proper processing conditions to apply during manufacturing to obtain completely consolidated, void-free thermoplastic resin composite parts.
The numerical study was based on the assumption of two-dimensional Darcy flow through stationary porous media. Fiber motion was neglected and quasi-steady state flow conditions were assumed. Inhomogeneity and anisotropy of fibrous preforms were allowed for. Due to the degree of geometrical complexity inherent to impregnation processes, the computational technique of boundary-fitted coordinate systems encompassing numerical grid generation was used and was found to be suitable for solving flow problems involving moving boundaries. The boundary conditions chosen for the investigation include constant applied pressure at the inlet, no-slip flow conditions along all walls, and vanishing shear stress along the impregnation front. Resin front/mold wall contact point movement was accomplished using either a no-slip based relocation algorithm or an imposed orthogonality method.
Results are presented in the forms of temporal impregnation front positions and neat resin depth distributions for two sample process configurations. From the analysis of this information, processing parameters are suggested with which the successful manufacturing of thermoplastic composite materials can be accomplished. The need for further experimental and analytical work in this area is also discussed.
Correlations Between Micromechanical Failure Processes and the Delamination Toughness of Graphite/Epoxy Systems
Authors: Hibbs MF , Bradley WL 
Published: December 2008

A combination of macroscopic delamination fracture toughness, scanning electron microscope (SEM) real-time fracture observations, and postfracture morphology were used to study the micromechanical processes of delamination failure in several graphite/epoxy systems.
Strain energy release rate GIc, GIIc, and mixed mode GI&IIc were obtained from unidirectional double cantilever beam specimens. Comparisons of these energy release rates with the resulting fracture surface mophology are used to clarify the relative importance of the formation of hackles and the fiber matrix interface adhesion to delamination toughness under Mode I, Mode II, and mixed Mode I & II loading conditions.
Real-time fracture observations of composite delamination in the SEM revealed the microprocesses of microcrack formation and coalescence. These observations coupled with GIc for the neat material, determined from compact tension specimens, provide insight on how resin toughness can be translated into composite delamination toughness.
The implications of hackle formation and their importance in the failure analysis of graphite/epoxy systems are discussed.
A Fractographic Investigation of the Influence of Stacking Sequence on the Strength of Notched Laminated Composites
Authors: Harris CE , Morris DH 
Published: December 2008

A study of the fracture processes in T300/5208 notched laminated composites concentrated on characterizing the influences of laminate stacking sequence on the formation of notch-tip damage zones and the subsequent mode of fracture of each ply of the laminate. The results revealed that laminate notched strength varied considerably with both a specified set of ply fiber orientations as well as the order in which the specific plies were arranged in the laminate. The fractographic examinations identified differences in the laminate fracture process which are believed to be the primary contributor to the differences in notched strength. The twelve laminates exhibited varying degrees of notch sensitivity as a result of the ability of a laminate to develop “subcritical” damage in a manner that relieved the high stress concentration at the notch tip.
The percent of laminate fracture by broken fibers was in direct correlation with the laminate notched strength. Laminates which were not characterized by damage zones containing major delaminations exhibited higher percentages of failure by broken fibers and higher notched strength. Conversely, when delaminations resulted in widespread ply uncoupling, relatively few plies of a laminate failed by broken fibers producing a weaker laminate.
Analysis of the In-Reactor Creep and Rupture Life Behavior of Stabilized Austenitic Stainless Steels and the Nickel-Base Alloy Hastelloy-X
Authors: Wassilew C , Ehrlich K , Bergmann HJ 
Published: December 2008

An overall evaluation of several in-reactor creep and creep-rupture experiments in BR2 and FFTF on pressurized tubes of the stabilized austenitic stainless steels 1.4970, 1.4981, 1.4988 and the Ni-base alloy Hastelloy-X is given in this report. Even at temperatures around and above 0.5 Tm the analysis of the data implies that for low stress levels the stress-induced preferred absorption (SIPA) creep process is the predominant deformation mechanism. The results show that the in-reactor rupture lives of the austenitic steels as well as the Ni-base alloy Hastelloy-X are reduced compared with the rupture lives of the corresponding material in the unirradiated and post-irradiation tested conditions, so that an additional damage mechanism via helium has to be assumed to account for the reduction in rupture life.
Analytical models have been developed, which accounts for the critical variables stress, temperature, and dpa rate and which describes in a more general way the in-reactor creep and creep-rupture life behavior of the materials mentioned above. The analysis of the results indicates clearly that the use of the unirradiated and post-irradiation data for predicting in-reactor creep and failures is invalid for these materials.
Long-Term Atmospheric Corrosion Behavior of Various Grades of Stainless Steel
Authors: Baker EA , Lee TS 
Published: December 2008

Several grades of stainless steel are evaluated after 26 years of exposure in the marine atmosphere at Kure Beach, NC. The alloys evaluated include 1% Ni + 16% Mn, 5% Ni + Mn, 7 to 10% Ni, 12 to 13% Ni + Mo, 12Cr and 17Cr alloys. The test specimens are in the form of flat panels, with spot welds, arc weldments, and Erickson cup deformations.
An assessment is made of the degree of rust, rust stain, and pitting attack on the boldly exposed surface.
The materials exposed 25 m from the ocean have from 20% rust, 70% rust stain, (Type 316 stainless steel) to 100% rust (Type 410 stainless steel). Surface pitting is insignificant (&lt;0.01 mm) on all material except Type 410 stainless steel, which has surface pits 0.06 mm in depth.
The materials exposed 250 m from the ocean have from 1% rust stain (Types 304 and 316 stainless steels) to 80% rust, 20% rust stain (Type 410 stainless steel), and surface pitting is insignificant.
The spot welded materials have a crevice area between the overlapped surfaces where significant pitting and intergranular corrosion occurs. The attack ranges between 0.08 to 0.17 mm in depth at the 25-m site, and between &lt;0.01 to 0.10 mm in depth at the 250-m site. Spot weld failure caused by corrosion is found only on Type 430 stainless steel.
The arc welded materials show no evidence of weld failure. The weld and HAZ did have greater rust and rust stain cover than the panel surface.
The materials with Erickson cups show no evidence of stress corrosion failure. However, pitting is more severe in the stressed areas.
Oxidation of Zircaloy-4 in Steam at 1300 to 2400°C
Authors: Prater JT , Courtright EL 
Published: December 2008

The oxidation kinetics of Zircaloy-4 in steam have been extended to 2400°C. Growth of the ZrO2 and α-Zr(O) layers display parabolic behavior over the entire temperature range studied; however, a discontinuity in the oxidation kinetics above 1510°C causes rates to increase above those previously established by the Baker-Just relationship. This increase coincides with the tetragonal-to-cubic phase transformation in ZrO2−x. No additional discontinuity in the oxide-growth rate is observed upon melting of Zr(O). The effects of temperature gradients have also been taken into account, and corrected values representative of near-isothermal conditions have been computed.Experiments have been performed in steam-hydrogen mixtures at 1565 and 1815°C. Concentrations of hydrogen up to 90 mol% have no effect on the oxidation kinetics. The rate-controlling factor appears to be the available flux of oxygen atoms incident to the reaction surface and is not dependent upon hydrogen content.
Charge Emission and Related Precursor Events Associated with Laser Damage
Authors: Becker MF , Domann FE , Stewart AF , Guenther AH 
Published: December 2008

Charge emission and surface photoconductivity were used to investigate possible precursors to laser damage, including surface cleaning and hardening. Experiments were conducted with a 1.06 micron ND:YAG laser with 5 nsec pulses. A wide range of samples were investigated, including diamond-turned copper mirrors, silicon wafers, and half-wave dielectric films of ThF4, Al2O3, and Ta2O5 on fused silica.
Charge emission at 1/10 of the single pulse damage threshold was observed for the copper mirrors. Declining emission for successive pulses was characteristic of surface cleaning. Emitted charge quantities increased monotonically with fluence prior to damage, but the charge emission was noisy with site-to-site variations. For silicon, damage was simultaneous with charge emission for both l-on-l and N-on-l tests. The damage morphologies for the two cases were distinctly different. Nonlinear absorption measurements were conducted on silicon for fluences below the single pulse damage threshold.
The two oxide dielectric films had gold electrodes evaporated on them leaving gaps of 0.75 to 2.0 mm for measuring surface conduction. Charge was collected from this configuration at 1/20 of the single pulse threshold. The charge quantity was very noisy and apparently uncorrelated with fluence. Surface hardening was observed for the ThF4 film and it did not emit until damage was initiated.
A Mixed-Mode Fracture Analysis of (±25/90n)s Graphite/Epoxy Composite Laminates
Authors: Law GE 
Published: December 2008

An investigation of the fracture mechanisms and behavior of sub-laminate cracking in graphite/epoxy composite laminates is presented. A series of laminates of the form (±25/90n)s is chosen for analytical modeling and compared with experimental results. By varying the number of 90-deg plies, indicated by n, several important and distinct fracture modes are identified. The thickness of the 90-deg layer is the single parameter that separates these fracture events. The present work focuses in particular on the mechanisms of transverse ply cracking and free-edge delamination.
The energy release rate approach of classical fracture mechanics is applied to describe the crack initiation fracture process. The cracking process is numerically simulated using a finite-element procedure formulated within the framework of ply elasticity and on the assumption of a generalized plane-strain state. The numerical procedure explicitly calculates the Mode I, Mode II, and Mode III components of the strain-energy release rate as a function of crack length. Unit mechanical and unit thermal load conditions are solved, and the results are superposed to obtain the general load case. The analytical model predicts the sequence of occurrence of the fracture modes and the critical onset loads.
The theoretical model is then correlated with published experimental data including tension tests on (±25/90n)s (n = ½, 1, 2, 3, 4, 6, and 8) laminate coupons manufactured using the T300/934 graphite/epoxy system and with fracture tests using double-cantileverbeam and cracked-lap-shear specimens. Good agreement is obtained between the theoretical and experimental results. The general nature of the present analytical method is readily applicable to composite laminates of more complicated structural geometry or loading conditions or both.