bluuebunny/crossref_metadata_2025_split huggingface dataset:
Epidemiology for Marketing Ski Safety
Authors: Kisser R , Goethals B , Wrobel M 
Published: March 2009

During one winter season all downhill skiing injuries occurring in a large Austrian skiing region were recorded. Interviews were carried out with patients as well as with skiers not suffering injury. Several subgroups with a significantly higher risk of injury, which need to be specifically addressed by the safety program, were identified.
To be able to formulate and apply a method of risk analysis for skiing regions as a precondition for the implementation of a comprehensive program to improve skiing safety, a new measure for the risk of injury (injury per vertical kilometer) was employed; it can be used to assess the risk to individuals as well as the risk associated with a given slope or a given day under certain weather conditions.
A skiing safety program along the lines of the World Health Organization “Safe Communities” scheme is proposed, with the main goal being to provide better information to the skiers on correct and safe behavior. It is recommended that the risk analysis employed to evaluate the programme be repeated annually.
Automatic Tracking of Bone Motion Using Ultrasound
Authors: Friedrich MT , Mote CD 
Published: March 2009

Severe knee injuries are reaching epidemic proportions in downhill skiing and are a major concern in other sports as well. Several experiments have used external joint motion measurement instruments to investigate the causes and mechanisms of knee injury. However, these measurements do not accurately represent the motion of the underlying bone (except under restricted test conditions) because of soft tissue motion of the transducer relative to the bone.
A new method is described that uses ultrasound imaging to quantify and account for soft tissue motion error by automatically tracking bone motion beneath the skin. The technique tracked in-plane motions of a lamb femur in its surrounding tissue with accuracies of 0.4 mm and 0.7 deg for motions within 10 mm and 6 deg, respectively, of an initial position. Errors in measurement of femur motion of a live test subject with an existing external transducer were computed with the method and were found to be large enough to suggest that these errors must be accounted for during in vivo tests.
Determination of Kinetic Friction and Drag Area in Alpine Skiing
Authors: Kaps P , Nachbauer W , Mössner M 
Published: March 2009

The coefficient of friction of skis on snow appears to be influenced by several factors, for example, speed, contact area, snow type, and ski properties. The purpose of this study was to determine simultaneously the coefficient of kinetic friction and the drag area in straight running on a slope with varying inclination and in traversing on an inclined plane. Experimental measurements were taken using photo cells for straight running and by film analysis for traversing. The skier was modeled as a particle that moves on the surface of a slope. The equation of motion with the algebraic constraints of the track of the skier represents a differential-algebraic equation which was solved numerically. The coefficient of friction and the drag area were calculated by minimizing the sum of the square errors between computed and measured time data.
For straight running, the computed coefficient of friction and the drag area were in the same range as obtained by other methods. For traversing, the coefficient of friction could be determined but not the drag area. The skier traversed in an upright position at a speed from 0 to 17 m/s. In this range of velocity the drag area is not constant. It corresponds to critical Reynolds numbers where a sudden drop in the drag coefficient occurs if the body segments are approximated by cylinders.
The results indicate that in both cases the applied method is adequate for determining simultaneously the coefficient of kinetic friction and the drag area if these parameters are independent of the velocity.
Loads Transmitted in the Practice of Snowboarding
Authors: Bally A , Taverney O 
Published: March 2009

The sport of snowboarding is increasing in popularity and seems to engender a relatively high risk of injury. The release binding specifically designed for snowboards, which at the moment is at the very beginning of its development, could contribute to a reduction of this risk.
The aim of the present study is to define criteria for the “retention” function of the release binding, and later to establish setting recommendations.
The loads (3 moments and 3 forces) transmitted to each boot via the binding were measured in the normal practice of snowboarding.
The peak loads measured had high scatter and correlated poorly with individual parameters such as weight, height, and snowboarding technique; hence the establishment of setting criteria is problematic at this time.
Release Level for Backward Release
Authors: Bally A 
Published: March 2009

Backward release seems to be one of the few remaining improvements still possible to existing mechanical bindings that can reduce the number and the severity of knee injuries, boot-top fractures, and contusions. An adequate choice of the setting is a necessary condition for the effectiveness of this release mode.
In order to evaluate the “softest” setting for backward release that does not cause inadvertent release of the binding (i.e., the “skiable minimum”), several series of field tests were carried out.
In the next step, the skiable minimum setting found by each test skier was correlated with the weight of the skier. For fast and aggressive skiers, the correlation was found to be poor, and a high level of scatter was observed. For other types of skiers the correlation was much better, and scatter was significantly lower.
Water SKi Binding Release Loads: Test Method and Results
Authors: Merala R , Piziali RL 
Published: March 2009

The existing technical literature is discussed along with injury data and a method for measuring the loads associated with release from water ski bindings.
Numerous case studies of water skiing-related lower extremity injuries have been published. There do not appear to be any statistically valid epidemiological studies or studies of water ski injury risk factors. An analysis of the 1990 water skiing injury data contained in the U.S. Consumer Product Safety Commission's (CPSC) National Electronic Injury Surveillance System (NEISS) is presented. Nationwide estimates of the number of water skiing related injuries associated with various portions of the body are made. An injury mode breakdown for various structures of the lower extremity is presented. The injury incidence rate is approximately 0.203 injuries per 1000 skier days for all injuries, and 0.041 injuries per 1000 skier days for possibly orthopedic injuries of the lower extremity.
A method for measuring the release loads of water ski bindings is described. A load cell that measures three orthogonal forces and three orthogonal moments is utilized. Human subjects remove their feet from the bindings in prescribed release modes while data are collected by an automated data acquisition system.
Forward bending and torsional release loads were measured for various types of bindings, including no-wrap, low-wrap and high-wrap bindings. As expected, in those situations where an axial force pushes the foot down against the ski, none of the bindings releases the subject's foot under torsional loading. Torsional release torques for the various bindings vary with the amount of heel liftup. The release loads measured are discussed in the context of release requirements for snow ski bindings. In general, the torques required to release from water ski bindings are smaller than the release torques recommended by snow ski binding release standards.
Coupling of Acoustic Emission and Electrochemical Noise Measurement Techniques in Slurry Erosion-Corrosion Studies
Authors: Oltra R , Chapey B , Huet F , Renaud L 
Published: March 2009

This study deals with the measurement and the subsequent signal analysis of acoustic emission and current noise recorded during continuous slurry erosion of a metallic target in a corrosive environment. According to a phenomenologic model, the localized corrosion results from the repetitive damage caused by particle impacts. The fluctuations of the acoustic signal and of the electrochemical signal both can be modeled as a shot-noise-like process.
The main purpose of this work is to compare two processing techniques for the fluctuating signals: time analysis (mean value) and spectral analysis (power spectral density [PSD] spectrum) to determine the more suitable signal treatment. Another purpose is also to quantify the balance between the mechanical wear and the corrosive damage of the abraded metallic target. It will be shown that the mean value of the RMS acoustic signal, A(t), and also the PSD of A(t), are related to the mechanical wear of the target and allow real-time measurement of the actual mechanical perturbation in terms of the mass of the ablated material.
On the Utilization of High Rate Pre-Cracked Charpy Test Results and the Master Curve to Obtain Accurate Lower Bound Toughness Predictions in the Ductile-to-Brittle Transition
Authors: Joyce JA 
Published: March 2009

Much recent work in the field of elastic-plastic fracture mechanics has been directed to developing a mechanics-based relationship between the onset of cleavage fracture in structural components and that of Charpy specimens. In the case of a commercial nuclear power plant the surveillance specimens are expected to have undergone an irradiation history equivalent to that of the pressure vessel, and hence to have the correct fracture toughness properties. The small size of these specimens, however, makes it difficult to obtain fracture toughness measurements that are transferrable to the much larger and higher constraint pressure vessel.
Application of proposed specimen size requirements[1] to this problem shows that for the typical fracture toughness and strength levels in nuclear pressure vessels, the pre-cracked Charpy specimen could lose constraint well before the onset of cleavage and the results obtained will then provide a very non-conservative estimate of the conditions required for the onset of cleavage in the vessel. Recent computational work by Koppenhoefer and Dodds[2] has strongly suggested, however, that if the specimen is loaded rapidly, additional constraint might be present which would allow the Charpy results to predict correctly the onset of cleavage in the nuclear pressure vessel. These authors predict that the presence of modest viscoplasticity will increase the deformation level at which constraint is lost and this in turn will allow Charpy size specimens to be adequate predictors of the onset of cleavage fracture in structural size elements.
In this paper pre-cracked Charpy specimens of A515 steel are tested at four different loading rates and five different temperatures in the lower ductile-to-brittle transition. The reference temperature, T0, is developed and shown to be very dependent on the loading rate and very independent of the temperature at which the data set was measured.
Characterization by Notched and Precracked Charpy Tests of the in-Service Degradation of Reactor Pressure Vessel Steel Fracture Toughness
Authors: Fabry A 
Published: March 2009

The current engineering and regulatory practice to estimate fracture toughness safety margins for nuclear reactor pressure vessels (RPV's) relies heavily on the Charpy V-Notch (CVN) impact test. The uncertainties of this correlation ("indexing") approach are known. Techniques to more directly estimate in-service toughness degradation using a variety of precracked specimens are under active development worldwide, with emphasis on their miniaturization. In the nuclear context, it is essential to address many concerns, such as: representativeness of the surveillance programs with respect to the vessel in terms of materials and environment, transferability of test results to the structure (constraint and size effects), conservatism of lower bound toughness estimation procedure, credibility relative to trends of existing data bases, etc.
An enhanced RPV surveillance strategy is being developed in Belgium. It combines state-of-the-art micromechanical and damage modeling to the evaluation of CVN load-deflection signals, tensile stress-strain curves and slow-bend tests of reconstituted, precracked Charpy specimens. A probabilistic micromechanical model has been established for static and dynamic transgranular cleavage initiation fracture toughness in the ductile-brittle transition temperature range; this model allows one to project toughness bounds for any steel embrittlement condition from the corresponding CVN and static tensile properties, using a single scaling factor defined by imposing agreement with toughness tests in a single condition. The outstanding finding incorporated by this “toughness transfer model” is that the microcleavage fracture stress is affected by temperature in the ductile-brittle transition and that this influence is strongly correlated to the flow stress: this does phenomenologically explain the shape of the KIc, KId-temperature curves as well as the actual magnitude of the strain rate and irradiation effects. Furthermore, CVN crack arrest loads and fracture appearance are also taken advantage of in order to estimate KIa degradation. Last, but not least, the CVN-tensile load-temperature diagram provides substantial information used for the modeling of in-service steel strengthening, of intergranular fracture susceptibility and other irradiation-induced and ageing effects.
Systematic application of this enhanced surveillance approach is expected to contribute to the improvement of the engineering and regulatory predictive capability, while making optimal use of the limited inventory of available surveillance material.
Fracture Toughness Derived from Small Circumferentially Cracked Bars
Authors: Scibetta M , Chaouadi R 
Published: March 2009

Small circumferentially Cracked Round Bars (CRB) are used to derive the fracture toughness of reactor pressure vessel steels. This cylindrical geometry is of practical interest for the nuclear industry as it only requires a small amount of irradiated material and as it is easy to test on a tensile machine.
This paper describes an experimental procedure to obtain fracture toughness measurements from CRB with a diameter of 10 mm. Emphasis is put on crack growth monitoring during rotating bending fatigue precracking, on the formulae used to analyse the load displacement trace of a fracture toughness test and on the correction to be applied to take the loss of constraint into account.
Experiments show that the method has the potential to derive fracture toughness valuesfrom the lower shelf to the lower transition region. Finite element analysis shows that the constraint of this geometry is generally lower than for bend specimens but is higher at higher load levels, allowing comparison to toughness data valid according to prevailing standards.
The Effects of the Configuration of a Weld-reconstituted Compact Tension Specimen on Fracture Toughness Determination
Authors: De Backer F , Gutiérnez-Solana F 
Published: March 2009

For integrity assessment of reactor vessels it is desirable to obtain elastic-plastic fracture mechanics properties of the vessel material and evaluate how such properties evolve during operation. The J-R curve provides a direct evaluation of these properties. As surveillance capsules normally do not contain specimens for that purpose, the possibility exists of using reconstituted compact tension specimens (CT). These specimens have inserts of the material concerned taken from the undeformed part of Charpy specimens, whether tested or not, and are reconstituted with electron-beam welding.
In order to evaluate the validity of the fracture toughness characterization with CT specimens reconstituted in this way, a comparison is made between the J-R curves obtained from CT specimens with and without insert. To analyze the influence of the specimen configuration on fracture toughness characterization, reconstituted CT specimens of different thicknesses and weld configurations are tested.
To help the analysis, plastic zone size estimations of reconstituted specimens are made to verify if the plastic zone interferes with the reconstitution weld. A clear qualitative relationship has been found between the interference of the plastic zone with the weld and the validity of the J-R curves obtained with reconstituted specimens.
Microspecimen Tensile Tests of A533-B Steel
Authors: Sharpe WN , Danley D , LaVan DA 
Published: March 2009

Miniature tensile specimens of A533-B steel were tested as part of the ASTM Cross-Comparison Exercise on Determination of Material Properties Through the Use of Miniature Mechanical Testing Techniques. The microspecimens are 3 mm long with a test section ∼0.3 mm square. Thin slices were cut from the supplied block of material by wire EDM and the microspecimens were machined from the slices with a benchtop CNC mill. Specimens were cut so that the tensile axes were in three orthogonal directions to investigate the anisotropy of the steel block.
A total of 47 microspecimens were pulled in a small test machine with an air bearing to reduce friction in the moving grip. Strain was measured directly on the specimen with a laser-based interferometric technique that used two tiny reflective indentations as gage markers. The entire stress-strain curve was recorded. In addition, five macrospecimens with cross-sections 3.2 mm square were tested in a conventional test machine using foil strain gages.
The coefficient of variation (ratio of standard deviation to mean value) of the microspecimen tests is on the order of 5% for both the yield and ultimate stresses. This sample block of A533-B steel is slightly anisotropic with regard to yield stress, but not ultimate stress. The yield stress — on the order of 440 MPa — and the ultimate stress — on the order of 600 MPa — are consistent with other results. The microspecimens showed yield and ultimate stresses approximately 5% lower than those measured on the macrospecimens.
Methods of Determining the Temperature Dependence of Primary Creep
Authors: Lewinsohn CA , Bakis CE , Tressler RE 
Published: March 2009

The service life of high-temperature composites and reinforcement fibers can be limited by creep, therefore it is desirable to understand the relationships between the creep strain and external variables. Due to load sharing between constituents or internal microstructural changes, a steady-state creep rate is never observed in some materials. Usually in these materials the creep rate decreases with increasing time. This is known as primary creep. Determination of the temperature dependence during primary creep is complicated by its dependence on time and/or strain. The suitability of various methods of analyzing primary creep data has not been addressed in detail before.
In this paper, three methods of determining the temperature dependence during primary creep are compared: the Arrhenius, the cross-cut, and the Sherby-Dorn methods. The methods are applied to creep data for silicon carbide fibers intended as reinforcements in high-temperature ceramic or metal matrix composites. The sensitivity of each method to measurement resolution and the capability of the creep laws associated with each method for predicting measured creep behavior are evaluated. The reliability of the computer software fitting routine is independently confirmed. The Sherby-Dorn and cross-cut methods are mathematically similar but the Sherby-Dorn method does not involve an arbitrary selection of experimental conditions, is less cumbersome to apply to large amounts of data, and uses a broader range of the available data.
Characteristics of Fatigue Life and Damage Accumulation of Short Fiber-Reinforced Polymer Composites
Authors: Yokobori AT , Takeda H , Adachi T , Ha JC , Yokobori T 
Published: March 2009

The relation between fatigue life and damage accumulation of fiber-reinforced polymer composite (FRP) is not yet clarified.
For practical use of FRP, it is necessary to relate the fatigue life to the mechanism of damage accumulation. Damage formation is controlled by the mechanical behavior of the interface between the matrix and fiber. We used short glass fiber-reinforced polycarbonate composite in our experiments. By using an in situ (real time) observational fatigue testing machine, we investigated the relationship between fatigue life and damage accumulation.
From these results, the fatigue life of this material was found to be dominated by damage accumulation which results from microfracture at the interface between the matrix and fiber. This microfracture is controlled by a cycle-dependent mechanism.
Composition of Incipient Passivating Layers on Heat-Rejecting Aluminum in Carboxylate- and Silicate-Inhibited Coolants: Correlation with ASTM D 4340 Weight Losses
Authors: Wagner FT , Moylan TE , Simko SJ , Militello MC 
Published: March 2009

X-ray photoelectron spectroscopy identified compositional differences between passivating layers initially formed in carboxylated coolants, in silicated coolants, and in a mixture thereof on well-controlled 319 aluminum surfaces under heat-rejecting conditions. The layer formed in silicated coolant was primarily silica, while that in carboxylated coolant was primarily hydrated alumina. Competition between inhibitor packages when carboxylated coolant was contaminated from the start with low levels of silicated coolant produced films which were not simply patchwise mixtures of the pure-coolant film types.
The surface analytical results aid the interpretation of subtle differences in weight losses under the ASTM Standard Test Method for Corrosion of Cast Aluminum Alloys in Engine Coolants Under Heat-Rejecting Conditions (D 4340) in carboxylated versus silicated coolants that became more pronounced when testing was carried out at a vehicle-like 50% coolant concentration. Results from time-resolved D 4340 measurements and from a two-step cleaning procedure further contribute towards proper evaluation of D 4340 weight losses in the different coolant types.