bluuebunny/crossref_metadata_2025_split huggingface dataset:
Irradiation Programs to Establish the Safety Margins of German Licensing Rules Related to RPV Steel Embrittlement
Authors: Ahlf J , Bellmann D , Schmitt FJ 
Published: December 2008

Under German licensing rules, irradiation-induced embrittlement of a reactor pressure vessel (RPV) in the core belt region is taken into account basically by determining the shift of the 41-J transition temperature of the Charpy impact energy versus temperature curve and then adjusting either the exclusion line of the modified Porse diagram, or the KIR curve, by this 41-J shift.
The accuracy limits of T 41 Jand Δ T 41 J determination are discussed and quantified. The transition temperature concept is shown to be conservative in the validity range of the respec-tive licensing rules because of the uncertainties in Δ T 41 J determination.
Investigations with respect to irradiation effects on fracture toughness deserve high priority in current programs. Results from a A 533-B 2 steel (HSST03) are presented, and the shift of the KIC curve is evaluated for two fluence levels.
Experiments related to the question of whether neutron flux density has an influence on embrittlement are briefly reported.
Foamed-in-Place Polyurethane Foam Insulation System Design and Application for Low-Temperature Storage Tanks
Authors: Duff MP 
Published: December 2008

Energy savings from reduced fuel consumption due to thermal insulation systems are frequently compared with the capital investment cost of the insulation system. Energy-saving thermal insulation programs for large storage tanks are not always implemented because the rate of return on the insulation investment may not be as attractive as the return on other investments competing for the same capital equipment expenditure dollars.
Seeking to develop a low-cost, thermally efficient, long-lived thermal insulation system that could increase energy savings and reduce first costs, the author selected foamed-in-place polyurethane foam as the system's basic insulation material. Insulation system details were selected to exploit the advantages and to overcome the disadvantages of polyurethane foam as a field-applied insulation material. A unique application method and application machinery were developed, specially suited to application to large, flat-bottomed, low-temperature storage tanks. The important features of the insulation system, Chicago Bridge and Iron Company's horizontal foamed-in-place (HFIP) insulation system, and the special application method are discussed in detail in the paper.
Thermographic Inspection of the Installation Quality of Retrofitted Wall Insulation
Authors: Tsongas GA , Ball TJ 
Published: December 2008

Infrared thermographic scans of the walls of 79 homes in Spokane, Washington, were made during the winter of 1983 as a means of observing the installation quality of retrofitted wall insulation. A special attempt was made to determine quantitatively the amount of void area that is typical in insulated walls since it can have a significant impact on thermal performance. Valid results were obtained for 30 of the test homes in this study, and the average uninsulated or void area was 9%, with a range of 1 to 35%. This result is in excellent agreement with those from other studies. For a 9% uninsulated area, estimates of the increase in heat loss relative to a fully insulated wall vary from a low of about 9% to as high as about 40%.
As suggested by the wide range in results, some of the retrofit wall insulation jobs were excellent and some were extremely poor. The newer installations were generally poorer. The important point is that it is clear from these results that wall insulation can be properly installed with little or no void area. Improved quality control on the part of the installers is certainly possible and needed. The fact that the average installation quality is relatively poor and the range in results is very large indicates that some kind of inspection program is advisable.
During this thermographic study, an assessment was also made of blown-in wall insulation installation problems. A number were observed, most of which could be eliminated with proper care and attention on the part of the installers. In addition, an effort was also made to locate high heat loss areas. One notable finding is that often the exposed portions of heated basement walls were uninsulated and therefore exhibited relatively high heat loss.
How the Plastic Behavior of Asphalt Mixtures Influences Pavement Life
Authors: Yandell WO 
Published: December 2008

It seems from the author's theoretical and applied research that uncertainties in pavement life prediction could be reduced by paying attention to the plastic behavior of its component materials. By ensuring that the relationship between the plastic behavior of the asphaltic concrete relative to that of the underlying layers (relative plastic behavior) is adjusted to an appropriate value, pavement life will be maximized. The sensitivity analysis reported in this paper gives an insight into the effect of relative plastic behavior on pavement life. The sensitivity analysis makes extensive use of the mechano-lattice stress-strain analysis of elastoplastic-layered media since it is able to detect the buildup of residual stresses and strains. These can have the effect of either increasing or decreasing pavement life.
It is therefore hoped that the highway engineer will be able to make use of this information to prolong pavement life. This he could do by designing the plastic behavior of the asphaltic concrete in the light of existing plastic behavior of the base and subgrade. Alternately the plastic behavior of the base and or the subgrade could be modified in the light of the plastic behavior of the asphaltic concrete. The plastic behavior of the asphaltic concrete may be controlled by modifying the rheological properties of the asphalt or of the asphaltic concrete mix.
Stress-Intensity Factors for Small Surface and Corner Cracks in Plates
Authors: Raju IS , Atluri SN , Newman JC 
Published: December 2008

Three-dimensional finite-element and finite-element-alternating methods were used to obtain the stress-intensity factors for small surface and corner cracked plates subjected to remote tension and bending loads. The crack-depth-to-crack-length ratios (a/c) ranged from 0.2 to 1, the crack-depth-to-plate-thickness ratios (a/t) from 0.05 to 0.2. The performance of the finite-element alternating method was studied on these crack configurations. A study of the computational effort involved in the finite-element-alternating method showed that several crack configurations can be analyzed with a single rectangular mesh idealization, whereas the conventional finite-element method requires a different mesh for each configuration. The stress-intensity factors obtained with the finite-element-alternating method agreed well (within 5%) with those calculated from the finite-element method with singularity elements.
The stress-intensity factors calculated from the empirical equations proposed by Newman and Raju were generally within 5% of those calculated by the finite-element method. The stress-intensity factors given herein should be useful in predicting crack-growth rates and fracture strengths of surface- and corner-cracked components.
Gaseous-Environment Fatigue Crack Propagation Behavior of a Low-Alloy Steel
Authors: Liaw PK , Leax TR , Donald JK 
Published: December 2008

Fatigue crack growth behavior of 4340 steel was investigated in gaseous environments: laboratory air, hydrogen, and helium. No significant effect of specimen orientation on the rates of fatigue crack propagation was observed. In each environment, increasing load ratio decreased the threshold stress-intensity range (ΔKth). The effect of load ratio on ΔKth in the air environment was, however, much more significant than that in wet hydrogen and dry environments (dry hydrogen and dry helium). At low load ratios (≲ 0.5), the values of ΔKth in the air environment were larger than those in dry environments. The ΔKth values in wet hydrogen were in between those in air and dry environments. At a high load ratio of 0.8, ΔKth was, however, insensitive to test environment.
The effects of load ratio and environment on fatigue crack growth rate properties are discussed in light of crack closure and hydrogen embrittlement mechanisms. While the effects of roughness-induced crack closure and hydrogen embrittlement on crack growth rates were found to be negligible, oxide-induced crack closure governed the kinetics of gaseous-environment, near-threshold crack propagation behavior. However, thick-oxide deposits in wet hydrogen did not cause high levels of crack closure.
Fracture-Mechanics Approach to Tribology Problems
Authors: Murakami Y , Kaneta M 
Published: December 2008

Two tribology problems are studied analytically from the viewpoint of fracture mechanics. One is an inclined semicircular surface crack under Hertzian contact loading and the other is an elliptical crack embedded parallel to the surface under Hertzian contact loading.
The behavior of crack opening/closure for a surface crack formed on lubricated rolling/sliding line-contact surface is analyzed theoretically on the basis of fracture mechanics. The crack opening displacement is controlled mainly by surface traction, contact pressure, and oil hydraulic pressure. Both the direction and the magnitude of the surface traction govern the oil seepage into the crack. The oil hydraulic pressure on crack faces is induced by two types of mechanism depending on the movement of contact pressure: the contact pressure transmitted directly by the oil to the crack faces and the oil blocking phenomenon caused by closure of mouth of crack. It was concluded by the analytical results that the oil seepage into a surface crack is the crucial factor which causes the pitting phenomena in rolling/sliding contact fatigue. From this point of view, the reason why pitting phenomena are more frequently observed on the follower surface than on the driver surface can be clearly explained.
The variations of three-dimensional, mixed-mode stress-intensity factors for an embedded elliptical crack under a Hertzian contact pressure moving over the surface are analyzed. The crack opening occurs near the leading crack tip as well as near the trailing crack tip during one pass of contact load. This crack opening behavior was confirmed by the experimental measurements. The directions of crack extension are also discussed.
Growth, Fracture, and Nondestructive Evaluation of Hydride Blisters in Zr-2.5 Nb Pressure Tubes
Authors: Leger M , Moan GD , Wallace AC , Watson NJ 
Published: December 2008

Rupture of a cold-worked Zircaloy-2 pressure tube in Pickering Unit 2 in 1983 occurred when a crack developed from an array of hydride blisters. These had formed on the outside surface of the pressure tube where it contacted the surrounding calandria tube. Fol-lowing this event, a comprehensive research program was initiated by Ontario Hydro. Its objective was to determine the consequences of pressure tube-calandria tube contact for channels in other reactors with Zr-2.5 Nb pressure tubes. The purpose of this paper is to present some of the results that have been obtained in the areas of blister growth, fracture, and nondestructive evaluation and to show how these results may be applied to Canada Deuterium Uranium (CANDU) reactor inspection.
Blisters were grown both on small specimens and on pressurized tubes. Blisters were ob-served to grow by gradual precipitation of hydride platelets throughout a volume that also increased with time. Blister growth rates increased rapidly with increasing average temperature. The hydride distribution in the blisters has been observed to be highly variable.
Four-point bending fracture tests were carried out on the small specimen blisters. These fracture tests indicate that blister size is a key parameter in determining the stress required to crack the blister with larger blisters cracking at lower applied stresses. This trend is shown to be consistent with previous finite-element modelling, which incorporated hydride plasticity.
Two of the pressurized tubes were inspected with a specially designed ultrasonic head, and responses were correlated with metallographic information. The ultrasonic inspection system was capable of detecting cracks as small as 0.15 mm deep in small blisters. This gives some expectation that inspection will be able to identify blistered tubes.
Link Between Stress Corrosion and Corrosion-Fatigue Behavior of Zircaloy in an Iodine Environment
Authors: Schuster I , Lemaignan C 
Published: December 2008

Three types of recrystallized Zircaloy-4 plates have been studied at room temperature in a methyl alcohol solution of iodine (iodine concentration = 10-3) and in dry air as a reference medium. Crack growth rates have been measured using double cantilever beam (DCB) and center notched (CN) specimens, depending on plate thickness. Fatigue life was obtained on smooth tensile type specimens.
Experimental data show that a corrosion fatigue phenomenon exists for Zircaloy in an iodine methyl alcohol solution; it is characterized by the following results: For fatigue life, a reduction in numbers of cycles to failure has been observed at intermediate stress levels, about a factor of 8, while there was no reduction of the fatigue strength. For crack growth rate, an increase has been found, by a factor of about 4, which had slight frequency and orientation dependence.
Extensive scanning electron microscope (SEM) fractography showed that the mechanism of corrosion fatigue of Zircaloy is rather unique: in contrast to classical corrosion fatigue, for which the increase in crack growth rate is due to the chemical enhancement of crack opening along the entire crack front, leading to wider striations, it was found in Zr-4 that the fracture surface consists of grains fractured by pseudo-cleavage as seen during stress corrosion cracking (SCC) crack growth, and other grains fractured by fatigue with striation spacings similar to those obtained in dry air at the same Delta K. For the initiation step, it was found that only intergranular cracking occurred on the free surface, until the stress intensity factor reached the threshold level for SCC or dry fatigue crack propagation, or both, at which point corrosion-fatigue started.
Effects of Microstructural Factors on Irradiation Growth in Zirconium-Niobium Alloys
Authors: Sadaoka N , Fuse M 
Published: December 2008

The irradiation growth mechanism of Zr-Nb alloys has been evaluated on the basis of a growth model in which point defect parameters obtained by molecular dynamics are used.
In the proposed growth model the effects of an acceleration of interstitial flow to the grain boundary are considered. This phenomenon is caused by specific microstructures in the Zr-Nb alloys. Experimental irradiation growth data for specimens with various microstructures were analyzed with the model. The calculated results indicated that the growth rate of Zr-Nb alloys, which became either positive or negative depending on the microstructures, could be simulated by this model adjusting the interstitial in-flow acceleration factor. Further negative growth rate was attributed to the increase of interstitial in-flow to the grain boundaries with specific orientations.
Jet-in-Slit and Vibratory Methods for Slurry Erosion-Corrosion Tests of Materials
Authors: Oka Y , Matsumura M , Yamawaki M , Sakai M 
Published: December 2008

Slurry erosion-corrosion tests were conducted on metallic materials of practical use by two kinds of testing apparatuses. One is a vibratory apparatus which uses a magnetostriction vibratory unit commonly used for the accelerated cavitation testing of materials. The other is a jet-in-slit apparatus by which a jet of slurry impinges on the test surface. The test results obtained by each apparatus showed a good agreement in the order of merit of the materials. The test results of the jet-in-slit apparatus agreed with the actual service performance of the material in relative magnitude of damage rates.
By making a comparison of the erosion-corrosion parameters between the testing apparatuses and the actual service conditions in the field, the testing conditions required for quantitative assessment of erosion-corrosion damage were discussed.
Measurements of the Forces Needed to Take Off Classic and Rear Entry Ski Boots
Authors: Binet M-H , Montillet B , Delouche G , Thomas M 
Published: December 2008

Because of concern with the difficulties encountered when removing rear entry ski boots from patients with lower limb injuries, an investigation was undertaken to determine if there are significant differences between the forces necessary to remove a rear entry boot and those necessary to take off a normal entry boot.
This laboratory study used an articulated foot with an ankle joint. The angles of the ankle's joint were measured, and the pulling forces necessary to remove the foot from various models of usual and rear entry ski boots were recorded.
Records were kept of several different people attempting to remove the boots. It was found that while it was possible to remove normal entry boots from the dummy's foot using reasonable force and without disturbing the foot's position, this was not the case with rear entry boots. In fact, according to the several different candidates, either extra forces were required or the position of the ankle joint had to be altered.
Practice and training play a great part in this removal. It has been proven that a doctor trained in the methods of removing boots from the injured skier uses a lower pulling force than an engineer not familiar with such methods.
Removing the boot without disturbing the ankle joint and using only reasonable force should be added to the existing standards concerning ski boots presently set by the industry.
Measurement of Strength and Loading Variables on the Knee During Alpine Skiing
Authors: Maxwell SM , Hull ML 
Published: December 2008

This study focuses on the prevention of knee injuries during snow skiing. To develop a technology of knee injury prevention, both the strength and loading on the knee during skiing activity must be known. This paper reports measurements of variables influencing both knee strength and loading of the joint. The strength variables measured included the degree of activity in six muscles crossing the knee, the knee flexion angle, and the force along the tibia shaft. Transducers included surface electrodes to monitor electromyogram signals indicating the degree of muscle activity and a goniometer to measure both hip and knee flexion angles. The complete loading on the knee was derived from a dynamometer, which measured the six load components at the boot-dynamometer interface. The transducer data were acquired and stored by a compact, battery-powered digital data acquisition-control system.
Three male subjects of similar physical size (nominal was 1.8 m and 75 kg) and skiing ability (advanced intermediate to expert) were tested under similar conditions. Each subject skied a total of four slalom runs—one snowplow and three parallel. The total time of each test was 21 s. Example data plots from different types of runs are presented and discussed. Based on observations from the data, necessary performance features for ski bindings offering improved protection from knee ligamentous injuries are defined.
Axial Rotation of the Lower Limb Under Torsional Loading: II. Parameter Identification of a Dynamic System Model
Authors: Johnson C , Hull ML 
Published: December 2008

In Part I of this two-part article, experiments that measured the response of the lower limb to dynamic, transient torsional loading applied at the boot/foot were described. Test variables included rotation direction, weight bearing, and joint flexion. For one of the three subjects tested, two approaches were explored for specifying parameters (that is, inertia, damping, stiffness) of a three-degree-of-freedom dynamic system model which best duplicated the measured response. One approach involved identification of linear parameters by means of optimization; the other approach entailed estimation. Parameter estimates, which included nonlinear, asymmetric stiffness functions, were derived from the literature. For both approaches, the efficacy of parameters was evaluated in terms of the resulting model's ability to duplicate the measured joint axial rotation. The optimization was undertaken to identify parameter dependence on test variables. Results indicate that, to a degree, parameter values are influenced by test variables. Results also indicate that the nonlinear, estimated model better approximates the experimental data than the linear, identified model.
In addition to identifying parameters of a three-degree-of-freedom model, parameters were also identified for a single-degree-of-freedom model where the motion variable was intended to indicate the rotation of the in vivo knee. It is concluded that the simpler model offers good accuracy in predicting both magnitude and time of occurrence of peak knee axial rotations. Model motion fails to track the measured knee rotation subsequent to the peak, however.
Metacarpophalangeal Sprain of the Thumb in Downhill Skiers: Ergonomic Study
Authors: Ledoux X , Ledoux A , Drouet N 
Published: December 2008

Sprain of the thumb metacarpophalangeal (MCP) joint is a frequent and serious injury in downhill skiers. A prospective study of 119 cases during the 1984-1985 winter season was carried out to determine the sprain mechanism and its correlation with the skier's ability, the type of ski pole, and the injury.
Four basic mechanisms were found to be involved. 1. Thumb dislocation by the strap when the skier's hand slid down the pole. 2. Impact of the abducted, antepulsed, and extended thumb in the snow, the hand moving forward, seen when the hand was ejected from the upper end of the pole. The design of the pole handle and the way it was gripped gave the hand a dangerous position with the thumb out stretched perpendicular to the palm. The injury would result from the thumb being stopped by the snow and the hand sliding forward. 3. In some falls, the hand rotated around the insertion of the strap, giving a contusion of the ulnar aspect of the MCP joint. 4. The thumb end could get caught in the snow when the falling skier tried to recover his balance with hand closed on the pole handle. It was concluded that: (1) the pole strap was a risk factor of unequal importance in competitors and the others, (2) “safety clips” were inefficient, (3) pole handles that surround the hand were dangerous, (4) during the fall the hand must be prevented from being ejected with the thumb abducted, and (5) some parts of existing pole handles were dangerous.
The characteristics of an ergonomic downhill ski pole handle are suggested. The corresponding prototype is demonstrated.
New Product Development and the Kids Confectionery Panel
Authors: Younkin RJ 
Published: December 2008

The Kids Confectionery Panel is an approach used to involve children early on in new product development. The belief is that by involving consumers as early as possible in the new product cycle, the probability of the success of new products is increased.
Children are recruited to the Panel based on possessing peer leader characteristics that are determined through a well-defined system of personal recommendations, telephone and written interviews, and personal group sessions. To date, after a year and a half of operation, the Panel consists of about 237 youths aged 8 to 18.
Results from the Panel have been encouraging and demonstrate its value in molding a consumer-driven mentality. The Panel is used for a variety of purposes, including idea generation, concept development, and benchtop product direction.