bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Anisotropy of In-Reactor Creep of Zr-2.5Nb Tubes
Authors: Causey AR , Elder JE , Holt RA , Fleck RG 
Published: March 2009

Creep specimens made from cold-worked Zr-2.5Nb tubes, fabricated with two different microstructures and crystallographic textures, were irradiated in the Osiris reactor in France in a fast neutron flux of about 1.8 × 1018 n ∙ m-2 ∙ s-1, E &gt; 1 MeV, at 553 and 585 K. The hoop stresses from internal pressurization range from 0 to 160 MPa. The basal poles were oriented in the radial-transverse plane of the tubes, either about 30° from the radial direction or primarily in the transverse direction; these are similar to the crystallographic textures in fuel sheathing and in CANDU reactor pressure tubes. Dislocation densities were similar while grain size and shape differ significantly.
The creep specimens were irradiated to fast neutron faiences up to 7 × 1025 n ∙ m-2. Creep rates were obtained from strain versus fluence plots and creep compliances were obtained from plots of the strain rates against hoop stress for each material at each temperature. The ratio of creep rates at the nominal temperature of 583 K to those at 553 K was similar to that derived from stress relaxation results at temperatures between 523 and 568 K.
The ratio of the biaxial creep compliance in the axial direction to that in the transverse directions is different for the two test materials; 0.0 to -0.1 for the fuel sheathing texture and 0.6 to 0.7 for the pressure tube texture. The results were analyzed using a self-consistent model developed previously to account for the contributions to the creep anisotropy of the three microstructure parameters involved here and for the grain interaction effects. The model, which was normalized to other test reactor and power reactor creep data for cold-worked Zr-2.5Nb tubes, predicted the ratio of the creep compliances to be -0.26 and 0.63, respectively. Thus, in agreement with previous conclusions, the creep anisotropy of Zr-2.5Nb tubes with pressure-tube-like crystallographic texture can be adequately predicted.
Aqueous Chemistry of Lithium Hydroxide and Boric Acid and Corrosion of Zircaloy-4 and Zr-2.5Nb Alloys
Authors: Ramasubramanian N , Balakrishnan PV 
Published: March 2009

The chemistry of the aqueous solution, surface chemistry of zirconium oxide (ZrO2), and the physical structure of the corrosion film have to be considered for an understanding of the mechanism of corrosion of zirconium alloys in aqueous solutions. Based on information available in all these areas, we are proposing a model for oxide growth on Zircaloy-4 fuel cladding and Zr-2.5Nb pressure tube material, in lithium hydroxide (LiOH) solutions with and without added boric acid (H3BO3).
Corrosion exposures were at 360°C and were short term of four-day duration. Concentration of lithium covered the range 0.7 to 3500 ppm and boron was added at 300, 600 and 1200 ppm. Weight gain, Fourier Transform InfraRed (FTIR) spectroscopy, and Secondary Ion Mass Spectrometry (SIMS) were used to characterize the oxide films. Potentiodynamic polarization measurements were made in separate tests at 315°C. The chemistry of LiOH-H3BO3 system at 300 to 360°C was evaluated from the ionization constants of water, LiOH, and H3BO3.
There is no simple relationship between pH and corrosion. In the absence of boron acceleration in corrosion, in these short-term tests, is observed at concentrations &gt;350 ppm Li for Zircaloy 4 and at &gt;60 ppm Li for Zr-2.5Nb. This is attributed to the modification of normal oxide growth by surface OLi groups formed by reaction with undissociated LiOH in the solutions. In the case of Zircaloy-4, the inhibition of accelerated corrosion by H3BO3 is greater than what can be accounted for by its neutralizing action on LiOH. The mechanism suggested is the removal of surface OLi groups by reaction with non-ionized H3BO3. Boric acid at high concentrations has a detrimental effect on the accelerated corrosion of Zr-2.5Nb alloy.
According to the model proposed for oxide growth, the corrosion behavior can be classified into two categories: (1) growth of post-transition type films under acceleration conditions where solution had access into the oxide and (2) growth of pre-transition films under non-acceleration conditions where the solution had not gained access into the oxide. For Case 1, the pores have to be &gt;2 nm in diameter so that interfacial double layer requirements are met for solution incursion in the oxide and the unleachable lithium and boron on the surfaces of oxide grains are from ion exchange and reactions with LiOH and H3BO3. In Case 2, the outer surfaces of oxide grains, which were exposed to the solution, have lithium and boron similar to that described for Case 1. The lithium and boron in the bulk of these pre-transition films are ascribed to LiOH and H3BO3 hydrogen-bonded to water and adsorbed on the surfaces of oxide grains.
Irradiation Effect on Fatigue Behavior of Zircaloy-4 Cladding Tubes
Authors: Soniak A , Lansiart S , Royer J , Mardon J-P , Waeckel N 
Published: March 2009

Since nuclear electricity has a predominant share in French generating capacity, pressurized water reactors (PWRs) are required to fit grid load following and frequency control operating conditions. Consequently, cyclic stresses appear in the fuel element cladding. In order to characterize the possible resulting clad damage, fatigue tests were performed at 350°C on unirradiated material or irradiated stress relieved Zircaloy-4 tube portions, using a special device for tube fatigue by repeated pressurization.
It appears that, for high stress levels, the material fatigue life is not affected by irradiation. But the endurance fatigue limit undergoes a decrease from the 350 MPa value for unirradiated material to the 210 MPa value for the material irradiated for four cycles in a PWR. However, this effect seems to saturate with irradiation dose: no difference could be detected between the two cycles' results and the corresponding four cycles' results. The corrosion effect and the load following influence were also investigated: they do not appear to modify the fatigue behavior in our experimental conditions.
Corrosion Optimized Zircaloy for Boiling Water Reactor (BWR) Fuel Elements
Authors: Garzarolli F , Schumann R , Steinberg E 
Published: March 2009

A corrosion optimized Zircaloy has to be based primarily on in-boiling water reactor (in-BWR) results. Therefore, the material parameters affecting corrosion were deduced from results of experimental fuel rod irradiation with systematic variations and from a large variety of material coupons exposed in water rods up to four cycles.
The major material effect is the size and distribution of precipitates. For optimizing both early and late corrosion, the size has to stay in a small range. In the case of material quenched in the final stage, the quenching rate appears to be an important parameter. As far as material chemistry is concerned, the in-BWR results indicate that corrosion in BWRs is influenced by the alloying elements tin, chromium, and the impurity silicon.
In addition to corrosion optimization, hydriding is also considered. A large variation from lot to lot under identical coolant condition has been found. The available data indicate that the chromium content is the most important material parameter for hydrogen pickup.
In-Reactor Corrosion Performance of ZIRLO™ and Zircaloy-4
Authors: Sabol GP , Comstock RJ , Weiner RA , Larouere P , Stanutz RN 
Published: March 2009

In-reactor and long-term autoclave corrosion data have been obtained on ZIRLO and three variants of Zircaloy-4: conventional (1.5% tin), low-tin, and beta-treated. In-reactor data from demonstration assemblies irradiated in the Virginia Power Company's North Anna Unit 1 reactor demonstrate the superiority of ZIRLO and, to a lesser extent, low-tin Zircaloy-4 over conventional Zircaloy-4. After two cycles of irradiation to an assembly burnup of 37.8 GWD/MTU, the average axial peak corrosion of ZIRLO was 32% that of conventional Zircaloy-4. Low-tin and beta-treated materials displayed average peak oxides 76% and 150% of that formed on conventional Zircaloy-4, respectively.
Autoclave corrosion tests of archive tubing have been performed in 633 K water, 672 K, 700 K, and 727 K steam, and in 633 K water containing 70 and 210 ppm lithium as the hydroxide. Correlation of the in-reactor data with the autoclave data indicates that the 633 K pure water test is the best qualitative indicator of in-reactor corrosion performance, and the 672 K steam test the poorest. Differences in in-reactor corrosion between ZIRLO and the Zircaloy-4 materials are consistent with the relative behavior of these materials in lithium hydroxide solutions. The relationships among the in-reactor and autoclave corrosion data, the microstructures, and the processing are discussed.
In addition to improved corrosion resistance, ZIRLO exhibits improved dimensional stability over Zircaloy-4. The in-reactor creep of ZIRLO is confirmed to be about 80% of that of Zircaloy-4, and irradiation growth is observed to be about 50% that of Zircaloy-4. These data are also presented and discussed.
Thermomechanical Cyclic Deformation of Metal-Matrix Composites
Authors: Karayaka M , Sehitoglu H 
Published: March 2009

A constitutive model is developed for unreinforced Al2xxx-T4 and silicon-carbide particulate (SiCp) reinforced Al2xxx-T4. Its capabilities are also outlined for predicting the cyclic, isothermal, and thermomechanical behaviors of the composite and its constituents. The constitutive model for unreinforced Al2xxx-T4 is also a unified model, because it combines creep and plastic strains as inelastic strains. The unified model for the matrix is combined with Eshelby's equivalent inclusion theory, which is modified to handle finite volume fraction and inelastic deformation, to simulate the behavior of the reinforced material. The behavior of Al2xxx-T4 (reinforced with 20% volume fraction of SiCp) was simulated at temperatures ranging from 20 to 300°C and strain rates of 3.10-5 1/s to 3.10-3 1/s. The model predicts the strengthening of the composite relative to the unreinforced matrix for isothermal and thermomechanical loading conditions.
The internal stress-strain behavior of the constituents (volumetric average) is reported. It is demonstrated that the matrix and the particulates experience a multiaxial stress state under uniaxial loading of the composite. The coefficient of thermal expansion mismatch between the reinforcement and the matrix contributes further to the multiaxial stress state. When the mechanical strain and temperature are in-phase, the transverse stress component in the matrix is out-of-phase with the longitudinal stress component. When the temperature and mechanical strain are out-of-phase, the transverse and longitudinal stress components are in-phase. The results on internal stress-strain fields provide insight into the interpretation of fatigue behavior of particle-reinforced composites at elevated temperatures.
The Application of Dynamic Mechanical Methods to T
g Determination in Polymers: An Overview
Authors: Chartoff RP , Weissman PT , Sircar A 
Published: March 2009

Many factors are involved with establishing Tg values from Dynamic Mechanical Methods. These can be grouped as: (a) instrumental factors (b) test frequency (c) material characteristics (d) choice of Tg criterion Instrumental factors may include temperature calibration, thermal gradients, sample size, clamping effects, and sample geometry. Increasing test frequency causes a shift of Tg to higher temperatures. Material characteristics include such factors as the degree of crystallinity in crystalline polymers, the degree of crosslinking in thermosets, the specific thermal and mechanical history of the material, and possible moisture effects. The Tg criterion selected relates to the subjective choice of viscoelastic function used to establish Tg. For example, the peak value of E" will give a different result than the peak tanδ.
In this paper we will review these various aspects of determining Tg, citing examples in each category which illustrate problems in assigning appropriate Tg values.
A Mechanical and Histological Analysis of the Bonding of Bone to Hydroxylapatite/Polymer Composite Coatings
Authors: Zimmerman MC , Boone PS , Scalzo H , Parsons JR 
Published: March 2009

Two experiments were conducted to evaluate hydroxylapatite/polymer composite coatings as bone attachment vehicles for polymers. In the first, bone attachment to two classes of hydroxylapatite (HA) coated polymers was evaluated mechanically and histologically. Particulate HA was molded into the surface of thermoplastic implants and cast into the surface of thermoset implants. Coated and uncoated specimens were implanted in the distal femurs of rabbits for four and twelve weeks. In a second experiment, a roughened surface polysulfone implant was created by imbedding particulate HA into a polysulfone (PS) rod. A second material was created where HA particles were imbedded in the PS rod and the surface of the composite was machined smooth. Smooth and coated implants in both experiments were implanted transcortically in the distal femurs of rabbits for four and twelve weeks.
After sacrifice, the bone/implant interface of all the implants was evaluated mechanically by means of a push-out test with a servohydraulic test system. Paired statistical analysis revealed significantly greater shear strengths for coated versus uncoated implants for both polymer systems (thermoplast and thermoset) at both time periods in the first experiment. The results of the second experiment showed a statistically significant increase in shear strength for the rough surfaced HA/PS implant when compared to the smooth surfaced HA/ PS implant at each time period. Histology at both time periods indicated direct bone apposition to the HA coating as compared to a fibrous encapsulation using the uncoated implants.
Evaluation of the Differences in Performing Particle Analysis with Water Instead of CFC Fluids
Authors: Welch PJ 
Published: March 2009

Most aerospace cleaning specifications require particulate analysis as part of the cleanliness verification process. Trichlorotrifluoroethane, CFC-113, is presently the test solvent of choice for cleanliness verification.
It has been proposed to use water to replace CFC-113 as the test solvent for cleanliness verification; however it has been speculated that the differences in the physical properties between the two fluids will result in significantly different results in the particle analysis.
A comparison of deionized water versus CFC-113 has been conducted for several types of sampling of components. This paper presents a description of the tests, the test results, observations, and conclusions regarding the subject.
Evaluation of Long-Term Thermal Performance of Cellular Plastics Revisited
Authors: Bomberg MB , Kumaran MK 
Published: March 2009

Since the Montreal Protocol has established restrictions on the use of substances, that deplete the ozone layer, evaluation of performance of foams manufactured with alternative blowing agents, partially halogenated hydrochlorofluorocarbons (HCFC) in particular, became a high priority issue.
This paper reviews the issues involved in the evaluation of long-term thermal performance under service conditions and presents an agenda for further research.
Forced Convection Effects in Fibrous Thermal Insulation
Authors: Silberstein A , Arquis E , McCaa DJ 
Published: March 2009

We relate experiments carried out both in the lab, in a guarded hot box, and in experimental test houses. It is shown that forced convection does not significantly affect the thermal properties of the insulation under the air velocities usually found in the cavities, unless the construction mode and/or workmanship allow multiple air entry zones, or discontinuities in the insulation or in the internal air barrier.
A computer model was also developed to help us understand the convective flow patterns inside the porous insulation, as induced by the forced convection above it. A fairly good agreement with experimental results could be obtained.
Pesticide Compatibility: The Effect of Carrier
Authors: Becher DZ 
Published: March 2009

The routine use of pesticide tank mixtures has increased the importance of formulation tank mix compatibility. Unfortunately, compatibility is very sensitive to the mixing and spraying conditions. Consequently, incompatibility occurs erratically in the field and is difficult to consistently reproduce in the laboratory. While compatibility in the field can never be totally predicted in the laboratory, the test method used in this work provides good predictions, while still allowing the testing of many combinations of pesticides and carriers with a reasonable effort.
It is known that the results of compatibility tests are dependent on the spray carriers used. It was not known whether tests with laboratory carriers would adequately predict field results. Therefore, samples of water and ammonium nitrate/urea liquid fertilizers were obtained from various parts of the United States and their effect on the compatibility of pesticide tank mixtures evaluated. Samples of nominally similar carriers gave very different compatibility results. The importance of using carriers which are representative of the ones used in the field when evaluating pesticide tank mix compatibility was confirmed.
Solvent and Surfactant Influence on Flash Points of Pesticide Formulations
Authors: Catanach JS , Hampton SW 
Published: March 2009

Intensified regulatory activity from various sources is guiding the consideration of higher flash (lower volatility) materials as preferred components in pesticide formulations. An update on the current issues surrounding storage and packaging of flammable and combustible liquids is presented.
For this paper, the term “components” refers to nonactive materials and includes solvent or solvent blends and surfactants used in the formulations. The purpose of this paper is to study the effect of multiple component solvent systems on flash point. Also, the effect of surfactants in the formulation will be reviewed.
Nonlinearity of flash points when different components are blended for the purpose of improving active solubility, formulation efficacy, evaporation rate, or other parameter is demonstrated.
Airtightness Characteristics of Electrically Heated Houses in the Residential Standards Demonstration Program
Authors: Parker DS 
Published: March 2009

This paper examines airtightness data from 623 electrically heated residential buildings in the Pacific Northwest. The Residential Standards Demonstration Program (RSDP) was designed to demonstrate the merits of energy-efficient construction techniques. The control houses were intended to be representative of current construction practice in the four-state region (Idaho, Montana, Oregon, and Washington). The Model Conservation Standards (MCS) houses incorporated energy efficiency features including measures to reduce air infiltration and provide ventilation with heat recovery. The RSDP houses were primarily built in 1984 and monitored in the 1985–1986 heating season.
The airtightness of the tested homes was found to highly variable. Based on interpretation of blower door tests with the LBL infiltration model, we conclude that the typical MCS home had an average natural air change rate of about 0.25 air changes per hour (ACH) versus a rate of 0.49 ACH for the typical control house.
Real-Time In-Situ Monitoring of Dredge Disposal Sites
Authors: Baldwin KC , Irish JD , Bokuniewicz HJ 
Published: March 2009

The University of New Hampshire is utilizing “smart,” remote, telemetering instrumentation for the real-time monitoring of the ocean environment. These techniques are being adapted to the dredged sediment disposal site monitoring problem, in particular, short-term monitoring during the discharge of dredged sediment and the long-term monitoring of the disposal mound after capping.
The goal of short-term monitoring is to collect sediment distribution and water property data that facilitate (1) studying the physical processes at the site, (2) monitoring the discharge operation, and (3) designing an efficient cap. To achieve this, the disposal site must be continuously monitored, and the lateral spread of dredged sediment, the amount of sediment deposited at and advected off the site, and the gross mound geometry and growth must all be estimated. The time and position of the dredged sediment during the actual discharge operation are recorded and relayed back to shore in real time as an artifact of this monitoring. This information is available to local and federal authorities charged with policing the disposal site.
The goal of long-term monitoring is to assess the dredged sediment mound and cap performance to insure that any contaminated sediment is safely contained. Satisfactory performance of a disposal site is defined here as small vertical settlement, no geotechnical instability, or no storm induced erosion effects. The detection of these effects drives the need for particular sensor and instrument configuration. The time series data acquired with these systems will allow making first order decisions regarding possible mound (dredged sediment/cap) performance inadequacies. The inadequacies may result in possible sediment resuspension and transport, and water column contamination.
Using modern developments in microprocessor-controlled instrumentation, acoustics and packet radio telemetry, general purpose, remote instrumentation is easily deployed for one year to monitor the ocean environment and telemeter data to shore in near real time. Acoustic and optical techniques for monitoring suspended sediment, as well as the usual physical oceanographic sensors can be interfaced to the bottom mounted instrumentation for these monitoring operations.
A Case Study of Geotomography Applied to a Detailed Investigation of a Highway Bridge Foundation
Authors: Saito H , Shima H , Toshioka T , Kaino S , Ohtomo H 
Published: March 2009

Three types of geotomographic surveys (seismic tomography, resistivity tomography, and radar tomography) were conducted at a highway bridge pier construction site to investigate rock characteristics. After the geophysical investigation, bedrock was excavated to construct the bridge foundation. Geological surveys and plate-loading tests were carried out on the excavated surface. The geophysical and geological results were generally in good agreement.
Seismic tomography can distinguish highly fractured rock from unfractured rock, and resistivity tomography and radar tomography can classify rock according to different water contents. The combined use of these three geotomographic surveys made it possible to detect the anomalous zone which was highly fractured and saturated.
Performance Testing of Selected Test Kits for Analysis of Water Samples
Authors: Spokes GN , Bradley J 
Published: March 2009

Chemical testing kits represent a convenient, reliable, inexpensive and fast option for chemists testing various types of aqueous samples including drinking water, ground water, wastewater and industrial process streams.
The three basic types of test kits are described. Easy-to-use chemical test kits are one type of kit that has found favor among its users. There is, however, a paucity of factual information about the accuracy and precision of these chemical test kits.
Data for selected CHEMetrics'[1] easy-to-use test kits are presented. Results of tests of colorimetric, photometric and titrimetric methodologies are described, including comparison data with EPA methods. Tests of nitrite-nitrogen, lead and quaternary ammonium compounds show that accuracy and precision may in some cases be lower than that of the standard method. The advantages and disadvantages of easy-to-use test kits are examined and the importance of good quality control in manufacturing is stressed. The benefits of kit tests are believed to outweigh any technical disadvantage provided the responsible chemist assures that the kit's accuracy and precision are adequate for the intended purpose.