bluuebunny/crossref_metadata_2025_split huggingface dataset:
Additive and Base Oil Effects in Automatic Particle Counters
Authors: Michael Paul W. , Wanke Thomas S. , McCambridge Michael A. 
Published: May 2009

Abstract
The U.S. Military specifies the use of Mil-PRF-2104 engine oil in the hydraulic system of certain nontactical military vehicles. Skid-steer loaders and other heavy equipment also use engine oils in their hydraulic systems. These vehicles are required to meet roll-off cleanliness specifications in order to improve hydraulic equipment reliability. Automatic particle counters are used to verify the cleanliness of these systems. Occasionally, particle counters detect phantom particles that cannot be removed by filtration. This paper examines the possible role of base oil and additive selection in the appearance of phantom counts. Filtered Group I and Group III base oils were doped with the components of an engine oil formulation. Particle levels were monitored before and after filtration using an on-line automatic particle counter. The results show that base oil selection has minimal bearing upon appearance of phantom counts while additive selection is a significant factor. Results from three different particle counters are compared. Two laser particle counters that operate by the light-blockage principle were found to produce phantom counts from polydimethylsiloxane antifoam additives. A direct-imaging laser particle counter classified antifoam particles as water droplets and was less susceptible to phantom particle interferences from silicone antifoam additives.
Retrospective Dosimetry of Fast Neutrons Focused on the Reactions 93Nb(n,n′)93Nbm and 54Fe(n,p)54Mn
Authors: Voorbraak W. P. , Kekki T. , Serén T. , Van Bockxstaele M. , Wagemans J. , Woittiez J. R.W. 
Published: May 2009

Abstract
An overview is given of practices for “retrospective” dosimetry based on extraction and counting of niobium and manganese present in typical pressure vessel materials. The main problem of counting structural materials is the overwhelming presence of the nuclide 60Co in the gamma-ray spectra of irradiated materials. Chemical separation of niobium and manganese is needed to determine the induced 93Nbm and 54Mn activities. Procedures have been developed for retrospective dosimetry applicable at normally equipped radiochemical laboratories. Chemical separation procedures have been applied followed by determination of the amount of niobium in dissolution after separation. Special attention has been given to the accurate counting of the very weak X rays of 93Nbm. Different techniques have been applied. Advantages, disadvantages, and the accuracy that can be achieved are discussed. Special attention has been given to the maximum accuracy that can be reached and the minimum amount of niobium that has to be collected to reach this accuracy.
Measurement of Corrosion Potentials of the Internal Surface of Operating High-Pressure Oil and Gas Pipelines
Authors: Demoz Alebachew , Papavinasam Sankara , Michaelian Kirk , Revie R. Winston 
Published: May 2009

Abstract
Corrosion potential is a fundamental electrochemical parameter critical to understanding the thermodynamic aspects of corrosion. Many corrosion theories are based on corrosion potentials. Corrosion potential is routinely and easily measured in the laboratory. In order to transfer this scientific knowledge from the laboratory to the field, it is necessary to determine the corrosion potential under operating field conditions. In this paper, the unique challenges measuring corrosion potentials in an industrial environment are described using measurements of the corrosion potentials of the internal surfaces of pipelines as examples.
Skiing and Snowboarding Injuries in Greece: A Two-Year Case-Control Study
Authors: Zacharopoulos Athanasios N. , Tzanakakis Nikolaos E. , Douka Maria I. 
Published: May 2009

Abstract
Purpose: To examine the incidence, types and patterns of snow sports injuries at Greek ski resorts. Material and Methods: Prospective case-control study at two major Greek ski resorts during 2004-5 and 2005-6 winter seasons, involving 978 injured skiers and snowboarders who asked for medical help and 775 uninjured controls randomly selected. The controls comprised every fifth person at the waiting queue towards the lifts, during weekdays, weekends and holidays, in all weather conditions. Results: The injury rate was 6.05 injuries per 1000 skier days, while 72.7 % of injuries occurred during alpine skiing and 27.3 % during snowboarding. Lower limb injuries were the commonest among skiers 43 % and females had a significant higher prevalence of injury than males (59 % versus 39 %). Snowboarders sustained more frequently upper limb injuries (49.2 %). Ligament sprains (22 %) and contusions (17.4 %) were commonest among skiers, whereas fractures (20.5 %) and contusions (15.4 %) were commonest among snowboarders. Knee and wrist injuries had statistically significant differences between skiers and snowboarders: knee 33.1 % versus 13.3 % and wrist 6.8 % versus 20 %. Most of injuries occurred during “free riding” (65 %), while the second cause of injury was collision for skiers (15.6 %) and jumps for snowboarders (23.5 %). Almost one out of five injuries (19.8 %) was lift related and 23.4 % of the lift related injuries happened when riding with an instructor. Most of injuries occurred at the end of the skiing day. Conclusions: Despite the high incidence of snow sports injuries in Greece the patterns and specific rates of injuries are similar to those previously reported in comparable studies. Many injuries were lift related, most of the injuries happened at the end of the skiing day and many people were injured when skiing/boarding with an instructor. So there is much room to update skiing safety in Greece providing safer slopes and adequate instruction.
Head Kinematics During Experimental Snowboard Falls: Implications for Snow Helmet Standards
Authors: Richards Darrin , Carhart Michael , Scher Irving , Thomas Reed , Hurlen Natalie 
Published: May 2009

Abstract
A study by Nakaguchi and Tsutsumi [“Mechanisms of Snowboarding-Related Severe Head Injury: Shear Strain Induced by the Opposite-Edge Phenomenon,” J. Neurosurg, Vol. 97, 2002, pp. 542–548] showed that 68 % of all snowboarders’ head injuries were associated with backward falls, with beginner and intermediate snowboarders constituting the majority of the injured. We previously fabricated a test apparatus that replicated the fall kinematics of a snowboarder during a back-edge trip. A Hybrid-III anthropomorphic test device (ATD) outfitted with a snowboard and snowboarding gear was accelerated to a typical intermediate snowboarder’s speed (30.5 ± 1.5 kph) and tripped resulting in a backward fall that terminated in a head-to-slope impact. This test protocol produced repeatable fall kinematics under realistic on-slope conditions. In this study, we characterized the fall kinematics and quantified head velocity in order to evaluate the helmet energy management requirements associated with a back-edge trip. Digital high-speed video recorded at 500 frames per second was used to quantify the snowboarder’s head kinematics: (i) prior to the trip; (ii) during trip phase; (iii) during free fall; and (iv) at ground impact. Translational energy of the ATD was rapidly converted to a combination of linear and angular energy during the trip phase. Although the speed of the ATD’s center of gravity decreased during the trip phase, the test data showed the absolute speed of the head increased rapidly during the fall as a result of the body’s induced angular rotation. The mean head velocity normal to the slope increased from approximately zero at fall initiation to as much as 37.1 kph during the fall (122 % of the initial velocity), and was 29.1 kph at snow contact (95 % of the initial velocity). Resultant head velocity peaked at 54.3 kph (178 % of the initial velocity), and was 38.2 kph at snow contact (125 % of the initial velocity). The data presented here may be useful for assessing drop height requirements for snow helmet evaluations.
Evaluation of Residual Stress Effects on Brittle Fracture Strength Based on Weibull Stress Criterion
Authors: Yamashita Yoichi , Minami Fumiyoshi 
Published: May 2009

Abstract
This paper studies the method for estimating the residual stress effects on brittle fracture of structural steel based on the Weibull stress criterion. First, brittle fracture tests were conducted for four-point bend notched specimens with and without compressive preloading. It is shown that the compressive preloading apparently decreases the critical crack tip opening displacement (CTOD). The critical CTOD of the preloaded specimen can be predicted from monotonically loaded test results based on the Weibull stress criterion. It has been found that the Weibull stress is an effective fracture parameter for brittle fracture initiation under tensile residual stress. Second, using wide plate specimens with and without welding residual stress subjected to uniform tension and three-point bend fracture toughness specimens, welding residual stresses effect on the brittle fracture strength is investigated. Experiments show that the critical CTOD of wide plate with welding residual stress is significantly smaller than that without residual stress. Constraint loss effect on CTOD of wide plate can be assessed by the equivalent CTOD ratio β. β is defined as β=δ3PB/δWP, where δ3PB and δWP are CTODs of the standard fracture toughness specimen and wide plate, respectively, at the same level of the Weibull stress. Fracture assessment result using β is shown within the context of failure assessment diagram. An excessive conservatism observed in the conventional procedure (β=1) is reasonably reduced by applying the equivalent CTOD ratio β.
Hydrogen/Plasticity Interactions at an Axial Crack in Pipeline Steel
Authors: Dadfarnia M. , Sofronis P. , Somerday B. P. , Robertson I. M. 
Published: May 2009

Abstract
The technology of large scale hydrogen transmission from central production facilities to refueling stations and stationary power sites is at present undeveloped. Among the problems which confront the implementation of this technology is the deleterious effect of hydrogen on structural material properties, in particular at gas pressure of 15 MPa which is the desirable transmission pressure suggested by economic studies for efficient transport. To investigate the hydrogen embrittlement of pipelines, a hydrogen transport methodology for the calculation of hydrogen accumulation ahead of a crack tip in a pipeline steel is outlined. This work addresses the interaction of hydrogen with an axial crack on the inside surface of the pipe. The approach accounts for stress-driven transient diffusion of hydrogen and trapping at microstructural defects whose density evolves dynamically with deformation. The results address the effect of hydrostatic constraint, stress, and plastic strain on the time it takes for the steady state hydrogen profiles to be established.
Tabletop Jumping: Engineering Analysis of Trajectory and Landing Impact
Authors: Shealy Jasper , Stone Fred 
Published: May 2009

Abstract
This study is an engineering analysis of skiers and snowboarders jumping what is known as a mid-sized tabletop feature at a ski resort. The analysis specifically looks at the trajectories and landing impacts of individuals while jumping mid-sized tabletop features (deck lengths 20 to 30 ft) at a ski resort. For the trajectory analysis, out of a total of 117 jumps by skiers and snowboarders that were observed, 57 jumps were analyzed using a radar gun to determine actual speed on the ramp, digital photography to document flight paths and landing points as well as jumper body position at the moment of take-off. For the impact analysis, a total of 31 jumps by an instrumented subject were videotaped; the landing impacts for 21 of these jumps were measured with triaxial accelerometers to measure the impact resulting from the landing at the boot top, chest, and head levels. With respect to trajectory analysis, the study concludes that simply knowing the ramp angle and take-off speed is not a sufficient dataset to predict where the jumper will land; alternatively, knowing the ramp angle and the landing point is an insufficient dataset to predict the take-off speed. The specific actions of the jumper with regard to raising or lowering the jumper’s center of mass while on the last part of the take-off ramp can significantly alter the effective take-off angle and subsequent flight trajectory. For the jumps observed in this study, the jumpers were able to routinely add or subtract as much as 15° to the actual take-off ramp angle, resulting in effective take-off angles much larger or smaller than the measured take-off angle. With respect to impact analysis, the study concluded that for jumps similar to the those observed in the trajectory analysis, when the jumper lands in an upright controlled manner, the resulting impact (measured in G units) at the boot level ranged from 50 to 100 Gs, with a mean of 75 Gs, it averaged 4.7 Gs at the chest and only 2.5 Gs at the head.
Injury Trends in Norwegian Ski Resorts in the 10 Year Period 1996–2006
Authors: Ekeland Arne , Rødven Andreas 
Published: May 2009

Abstract
A central ski patrol-based registration of skiing and boarding injuries was performed by the Norwegian Ski Lift Association during the winter seasons 1996/1997–2005/2006. Totals of 31 175 injured skiers/boarders and 21.898 million skier/boarder days were recorded during the ten seasons, giving an injury rate of 1.4 injured per 1000 skier/boarder days. Most of the injuries occurred during alpine skiing (49–58 %). Snowboarding injuries peaked with 45 % in the middle of the period decreasing to 35 % the last two seasons. Telemark skiing and skiboarding each accounted for less than 10 % of the injuries. Wrist injuries were most common among injured snowboarders and knee injuries among injured alpine skiers. The percentage of knee injuries was almost twice as high for females compared to males throughout the period (p&lt;0.001). The prevalence of lower leg fracture for injured alpine skiers ⩽12 years decreased from 20 % to 13 % in the period (p&lt;0.001), whereas the corresponding prevalence for teenagers and adults was relatively stable at 3–5 %. Injuries in terrain parks increased to 20 % of all injuries at the end of the period. The use of helmets among injured skiers/boarders increased from 11 % to 44 % in the 10-year period (p&lt;0.001), whereas the prevalence of head injuries decreased from 19 % to 17 % (p&lt;0.003). In conclusion, the injury rate has been almost constant during the last six seasons in Norwegian ski resorts. The prevalence of lower leg fracture has decreased in injured alpine skiers ⩽12 years. The use of protective helmet has increased by injured skiers/boarders and the prevalence of head injuries has decreased.
Crystalline Silica Analysis: A Comparison of Calibration Materials and Recent Coal Mine Dust Size Distributions
Authors: Page SJ 
Published: May 2009

Abstract
Since 1982 standard calibration materials recommended for respirable crystalline silica analysis by the Mine Safety and Health Administration (MSHA) P7 Infrared Method and the National Institute for Occupational Safety and Health (NIOSH) X-ray Diffraction (XRD) Analytical Method 7500 have undergone minor changes in size distribution. However, a critical assumption has been made that the crystalline silica in ambient mine atmosphere respirable dust samples has also remained essentially unchanged in particle size distribution. The objective of this work, therefore, is to compare recent particle size distributions of underground coal mine dust and the silica component of these dusts with estimated aerodynamic particle size distributions of calibration standard materials MIN-U-SIL 5, Berkeley 5, and SRM 1878 used by two crystalline silica analysis techniques. This work provides resolution to a previously reported discrepancy involving the proper sample dilution for the particle sizing method used.
Dust impactor sampling data for various locations in 13 underground coal mines were collected between 1991 and 1998 and analyzed for the respirable mass median aerodynamic diameters. The data suggest that the MSHA P7 Method will underestimate the silica content of the sample by at most 8.5 % in the median size range of 0.9–3.6 µm and that it is unlikely one would obtain any significant error in the MSHA P7 Method analysis when the method uses Berkeley 5, MIN-U-SIL 5, or SRM 1878 as a calibration standard material.
The results suggest that the NIOSH Analytical Method 7500 would be more appropriate for a dust sample that is representative of the total (no cyclone classifier) rather than the respirable airborne dust, particularly since the mass fraction in the size range below 4 µm is usually a small percentage of the total airborne dust mass. However, the NIOSH Analytical Method 7500 is likely to underestimate the silica content of an airborne respirable dust sample by only 5–10%. The results of this study also suggest that any changes that may have occurred in the median respirable size of airborne coal mine dust are not significant enough to cause any appreciable error in the current methods used for respirable crystalline silica analysis.
An Evaluation of Aerosol- and Liquid-Generated Silica Samples for Proficiency Analytical Testing
Authors: Hayes T , Parish H , Key-Schwartz R , Popp D 
Published: May 2009

Abstract
SRI International has prepared dynamically generated silica samples since 1980 for the National Institute of Occupational Safety and Health (NIOSH) and the American Industrial Hygiene Association (AIHA) Proficiency Analytical Testing (PAT) programs. Aerosol-generated samples were developed in 1980 to more closely approximate real world samples and to improve intrabatch precision. Liquid-generated samples may provide tighter control limits, and this method has been reexamined as the generation procedure of choice. Sample preparation procedures have also been investigated to minimize analytical uncertainty and, hence, obtain a true evaluation of the sampling error. Samples were analyzed by SRI, NIOSH, and the Wisconsin Occupational Health Laboratory, using X-ray diffraction or Fourier transform infrared spectrometry (FTIR). Results were plotted and statistically evaluated, then compared to the existing PAT interlaboratory database.
Radiation-Induced Stress Relaxation of Welded Type 304 Stainless Steel Evaluated by Neutron Diffraction
Authors: Obata M , Root JH , Ishiyama Y , Nakata K , Sakamoto H , Anzai H , Asano K 
Published: May 2009

Abstract
The welded Type 304 stainless steel specimens were neutron-irradiated up to 2 × 1025 n/m2 (E &gt; 1MeV) at 561K in the Japan Material Testing Reactor (JMTR). The residual stresses in the test specimens were measured by neutron diffraction, and the radiation-induced stress relaxation was evaluated from the change of stress distributions along the direction transverse to the weld bead. The magnitudes of σX (transverse to the weld) and σY (longitudinal to the weld) residual stresses decreased steadily with increasing neutron fluence. The irradiation dose dependence and the mechanism for the relaxation were examined using an equation derived from the irradiation creep equation. There was a steep stress relaxation, which might correspond to transient creep, at the early stage of neutron irradiation near the weld, and the different radiation-induced relaxation behaviors could be observed depending on the distance from the weld. The radiation-induced stress relaxation for welding-induced residual stress, which was generated under a three-dimensional restriction, indicated the tendency to be slower compared to the fundamental results for mechanically applied stress.
Flow Localization Processes in Austenitic Alloys
Authors: Wu X , Pan X , Li M , Stubbins JF 
Published: May 2009

Abstract
Austenitic alloys are widely used for structural component applications in high irradiation environments. In general, they are more resistant to embrittlement than other classes of structural alloys, particularly at ambient and intermediate temperatures. Nevertheless, this class of materials suffers from highly localized flow when irradiated to moderate dose (∼ 1 to 5 dpa) at temperatures between 150 and 400°C. The loss of ductility is normally exhibited by very low values of uniform elongation in tensile tests. The processes that lead to plastic instability are examined here for several face centered cubic materials and alloys. It is found that there is a critical stress level at which necking initiates. This critical stress level is not influenced by irradiation exposure. However, irradiation exposure, which increases material yield strength, does result in proportional reductions in uniform elongation. Most of the materials examined here exhibit a bilinear strain hardening behavior. This leads to direct correlation between the material yield strength and the uniform elongation.
Influence of Cold Rolling Threads Before or After Heat Treatment on High Strength Bolts for Different Fatigue Preload Conditions
Authors: Horn NJ , Stephens RI 
Published: May 2009

Abstract
SI grade 12.9 high strength steel bolts were used to investigate the fatigue behavior of bolt threads rolled before/after heat treatment using two different thread profiles and two different high preload values. Bolts were 3/8 UNRC-16 (coarse) and 3/8 UNRF-24 (fine) and preloads were taken as 75 and 90% of proof stress. Axial forces were applied through the nut. Axial and transverse residual stresses near the thread root were measured using X-ray diffraction. Most fracture surfaces contained crescent-shaped cracks and SEM evaluation indicated all fatigue crack growth regions contained multiple facets with no striations. Rolling after heat treatment caused little to no increase in fatigue resistance for the coarse threads. However, the fine threads finite fatigue life increased by factors of 2 to 5 and fatigue strengths based on Sa at 107 cycles increased by 40 and 50% for the 90 and 75% of proof stress preload, respectively. These are significant increases considering the very high preloads or R-ratios. The greater preload gave better fatigue resistance when based on the maximum stress, Smax, and lower fatigue resistance when based on the alternating stress, Sa Based on Smax, fatigue strengths at 107 cycles for 90% of preload were equivalent to or greater than the actual proof stress. Smax at 107 cycles for fine threads rolled after heat treatment with 75% of proof stress was also greater than the actual proof stress. The above results can be attributed to different thread root radii, thread region smoothness, original residual stress from rolling after heat treatment, and residual stress relaxation from the high preloads.