bluuebunny/crossref_metadata_2025 huggingface dataset:
Hierarchical Scales in Landscape Responses by Forest Birds
Authors: Niemi GJ , Hanowski JM , Danz N , Howe R , Jones M , Lind J , Mladenoff DM
Published: April 2008

Selection of habitat by birds is manifest at different geographical scales. Most bird communities in forested ecosystems of the northern hemisphere are comprised of migratory species that represent more than 70% of the species and individuals within a forest patch. Historically from the 1950s to 1970s most studies were focused on the response of forest birds at the patch or forest stand scale. Since the 1980s, field studies have determined both microhabitat needs (e.g., individual trees or species) or the importance of entire landscapes in which populations occur. Advances in computation power, remote sensing, geographic information systems, and multivariate analytical techniques have greatly enhanced our understanding of bird habitat associations at these multiple geographic scales. Based on results for over 50 species, we illustrate the responses of forest birds in the Great Lakes region at three spatial scales: microhabitat, forest patch, and landscape. Management opportunities are easiest to implement at the forest patch scale, but cognizance of natural disturbance regimes, basic life history needs, and landscape context can enhance opportunities for conserving native forest bird assemblages.
Type, Scale, and Adaptive Narrative: Keeping Models of Salmon, Toxicology and Risk Alive to the World
Authors: McCormick RJ , Zellmer AJ , Allen TFH
Published: April 2008

In modern day toxicology, problems arise in modeling complex ecosystems, such as the Columbia River system. There remain an abundance of models for which responsibility of assumptions is unaccounted and between which cohesion lacks. Models should be evaluated independently, taking into mind issues of scale and type in order to make sure the models actively change in accordance with the adaptive system they try to represent. The authors here suggest using narratives to weave together the inconsistent models. Narratives allow scientists to take responsibility for their assumptions and facilitate improved coherence between models. Problem solving engines, such as soft systems methodology, may then be used to achieve these modeling and adaptive management goals.
Habitat Ranking System for the Threatened Preble's Meadow Jumping Mouse (Zapus hudsonius preblei) in Eastern Colorado
Authors: Ryon TR , Bonar MJ , Sherff-Norris KL , Schorr RA
Published: April 2008

An objective, quantitative method was devised to delineate and rank habitat of the federally listed Preble's meadow jumping mouse in the Monument Creek watershed in eastern (El Paso County) Colorado. Methods involved review of field studies and devising a set of instructions to develop a habitat map based on field study results. Information was included from field research on individual mouse movement and home range, as well as the habitat continuum that includes vegetation characteristics at sites that supported high densities of Preble's mice as well as those that had low densities of mice. Preble's mice are considered to use lush riparian vegetation as well as dense upland vegetation adjacent to riparian areas. Radio telemetry data were reviewed to establish a relationship between riparian edge and the extent (i.e., linear distance from riparian edge) to which Preble's mice use upland areas. Riparian vegetation mapping, aerial photos, and hydrology were used as a basis for mapping habitat. The ultimate purpose of the Habitat Ranking System is to provide a foundation for sound conservation of habitat in El Paso County.
Approaches to Spatially-Explicit, Multi-Stressor Ecological Exposure Estimation
Authors: Hope BK
Published: April 2008

When assessing risks posed by chemical toxicants, risk assessors must estimate a receptor's level of exposure to them in abiotic (soil, water, etc.) and biotic (tissues, prey items) media. However, any free living terrestrial receptor is constantly challenged to avoid or minimize physical and biological stressors. Thus a receptor at a contaminated site may also face challenges from physical and biological, as well as toxicant, stressors. Toxicant stress may pose a risk on its own, or may add to risk posed by physical and biological stressors that are a part of a receptor's everyday existence. It is generally recognized that the relative spatial positions of receptors and contaminated media can strongly influence estimates of exposure and hence of risk. How a receptor moves with respect to habitat directly influences how it may be affected by one or more stressors. This paper was prepared to provoke further discussions on: (1) the benefits associated with attempting to estimate a terrestrial receptor's exposure to multiple stressors as that receptor moves through both space and time and (2) the challenges posed by attempting such an estimate in the context of a typical production ecological risk assessment.
Properties of Controlled Low-Strength Materials Made with Wood Fly Ash
Authors: Naik TR , Kraus RN , Siddique R , Chun Y-M
Published: April 2008

Controlled low-strength materials (CLSM) were made in the field using one source of wood fly ash as a major component. CLSM Mixtures S-1 and S-3 contained cement, wood fly ash (81 and 89%, respectively, by mass of cementitious materials [Cm]), and sand; whereas, Mixture S-2 contained cement, wood fly ash (11% of Cm), Class C coal fly ash (67% of Cm), and sand. Mixtures S-1, S-2, and S-3 showed respective compressive strength values of 0.8, 0.3, and 0.6 MPa at 28 d, and 1.4, 14.4, and 1.0 MPa at one year. Combination of wood and coal fly ashes might have caused the drastic increase in the strength of Mixture S-2 at late ages. The respective water permeability values of Mixtures S-2 and S-3 decreased from 68 and 33 μm/s at 63 d to 6 and 12 μm/s at 227 d due to the improvement of microstructure of these CLSM mixtures.
Use of Botswana Fly Ash as Flowable Fill
Authors: Sahu BK , Swarnadhipati K
Published: April 2008

In the present work high fly ash content flowable fill of Botswana fly ash has been investigated. The lime and cement in the proportion of 3%, 6%, 9%, 12%, and 15% and water equal to 125% of its liquid limit was mixed with fly ash to produce self leveling fill. The safe bearing capacity (S.B.C) of these fills was determined in the laboratory after 1,2,4, 7, and 15 days using drop test and the Dynamic Cone Penetration (DCP) test were determined in the field after 1, 7, and 28 days. The California Bearing Ratio (CBR) and Unconfined Compressive Strength (UCS) of the fills were calculated from DCP values using empirical correlations. It was noted that there is no significant effect of lime or cement on seven days strength. The safe bearing capacity attained after seven days were approximately two to four times the safe bearing capacity of most well compacted earthen backfill materials. The CBR of the fills after seven days was found to be more than the requirement for the base and sub base for roads. The findings suggest that the high fly ash flowable fills of Botswana fly ash can successfully be used without any addition of lime or cement.
Field Demonstration Test on Construction and Strength of Flexible Pipe Drainage System Using Flowable Fill
Authors: Masada T , Sargand SM
Published: April 2008

A team at Ohio University recently completed a research project related to flowable fill. The main objective of the project was to evaluate the feasibility of constructing an economical drainage pipe system using a flexible thermoplastic pipe and flowable fill. The project tasks were divided into three phases (laboratory characterization tests, field demonstration tests, and engineering analysis). This technical paper summarizes mainly data obtained during one of the Phase 2 field demonstration tests conducted at the load frame site, utilizing a corrugated HDPE pipe, flowable fill, and a variety of sensors. The test results confirmed many previously cited advantages of using flowable fill as pipe backfill material and also showed that some potential problems could be overcome easily. Finite element analysis simulated the field performance of the flexible pipe-flowable fill system reasonably well. In summary, it was concluded that it was quite feasible to construct a sound subsurface drainage system using flexible pipe and flowable fill.
Freeze-Thaw Effects and Gas Permeability of Utility Line Backfill
Authors: Hooper FP , Marr WA , Drefus RB , Farrag K
Published: April 2008

Backfill materials used in utility trenches must maintain physical and mechanical integrity when subjected to the seasonal effects of freezing and thawing. Materials used over gas utility lines must also have adequate permeability to allow any leaking gas to flow upward and out. To help determine how soils and flowable fills might perform as backfill over utility lines, we conducted laboratory tests to measure the permeability of backfill materials before freezing, during freezing, and after thawing. The two materials investigated in this study were a silty sand, and a flowable fill made with Type F fly ash. Our work also examined the susceptibility of these materials to frost heave and thaw weakening. An apparatus and standard test method for performing permeability during freezing and after subsequent thawing did not exist. We developed a method by adapting the ASTM Standard Test Method for Frost Heave and Thaw Weakening Susceptibility of Soils (D 5918) and the ASTM Standard Test Method for Measurement of Pneumatic Permeability of Partially Saturated Porous Materials by Flowing Air (D 6539). Although more data are needed to confirm specific conclusions determined from this study, the test method developed here appears to be useful for evaluating the effects of freeze-thaw on backfill materials for utility trenches. Additional work is needed to demonstrate whether these laboratory results correspond to actual field conditions.
Fluorescence Imaging for Investigating the Efficiency of Formulations, Adjuvants, and Application Systems
Authors: de Ruiter H , van der Schoor R , Jalink H
Published: April 2008

Several herbicides reduce, directly or indirectly, the efficiency of photosynthesis of plants. As a consequence, the fluorescence of the chlorophyll increases. The relative increase of fluorescence [(Fm-Fo)/Fm] can be used to compare the influence of formulations and adjuvants on the activity of herbicides. This procedure allows the accurate and non-destructive screening of sprayed plants in the first minutes and hours after treatment. A new development is the automated imaging and quantification of the relative increase of fluorescence at the whole plant level. Use of a robot-arm enables a laser-camera to take pictures of the chlorophyll fluorescence of different plants with short time intervals between plants. This procedure makes it possible to screen hundreds of plants simultaneously. Individual pictures can be used, or pictures can be used to compose a video demonstrating the dynamics of the herbicide action. The potency of this technology for monitoring bentazon, glufosinate and glyphosate action is demonstrated. In addition to investigating the influence of formulations and adjuvants on herbicide activity, the fluorescence imaging technology can be used to monitor phytotoxicity of formulations and spray application parameters like water volume and drop size.
New Value-Added Polymeric Dispersants and Uses Thereof in Agricultural Formulations
Authors: Narayanan KS , Jon DI , Patel J
Published: April 2008

Polymeric dispersants are dispersants of choice for formulating suspension concentrates, suspoemulsions, and solid delivery systems (WP, WDG, and Tablets). We have developed a new line of polymeric dispersants, as 25 % aqueous solution, based on partially neutralized methyl vinyl ether maleic acid half esters (ethyl/butyl) copolymers (MVE-MAHE), (with trade name EASY-SPERSE®2). They were used in formulating suspension concentrates and aqueous dispersions for a host of active ingredients like herbicides, insecticides, fungicides, and other growth regulators, organic dyes, inorganic pigments, including certain water-insoluble polymers. Some of these dispersions also showed suspensibility above 80 % and rainfastness at use level concentrations.

Other commonly used polymeric dispersants are: Lignosulfonates, Naphthalene sulfonate formaldehyde condensate (NSFC), Poly acrylates, and olefin maleic acid co-polymers. Their film forming properties and binding efficacy can be improved when used with pyrrolidone co-polymers.

Our recent findings show synergy between vinylpyrrolidone homo/co-polymers and commonly used polymeric dispersants as above. Further, a combination of Polyvinylpyrrolidone and polymeric dispersants showed built-in rainfastness in suspension concentrates. Examples of prototype formulations and a working model explaining the synergistic role of polyvinylpyrrolidone are provided. Solid composites from Polyvinylpyrrolidone and MVE-MAHE were prepared via spray drying the liquid slurries. The solid dispersants with Polyvinylpyrrolidone incorporated will be useful in formulating solid delivery systems.
Advances in ICP-MS Technologies for Characterization and Ultra-Trace Speciation as a Tool for the Petroleum Industry
Authors: Paszek J , Mason KJ , Mennito AS , McElroy FC
Published: April 2008

Particular elements can, even at trace levels, impact product quality, deposit formation, and regulatory compliance. Characterization of trace and ultra-trace level constituents in aqueous and/or organic matrices has often required the need to employ more than one analytical technique. In recent years, improvements in ICP-MS technologies have made it a preferred technique for multi-element trace level characterization in a variety of matrices. Coupling ICP-MS with various liquid chromatography techniques has enabled a unique capability to speciate organo-metallics at ppb levels. This paper will show how ICP-MS has been successfully used to measure ppb levels in refinery effluent streams. It will demonstrate how hyphenated ICP-MS techniques assisted in development of bioremediation options for selenium removal in wastewater treatment plants.
Rotrode Filter Spectroscopy: A Recently Improved Method to Detect and Analyze Large Wear and Contaminant Particles in Fluids
Authors: Lukas M , Yurko RJ , Anderson DP
Published: April 2008

Routine spectrochemical analysis of used oil samples with rotating disc electrode (RDE) or inductively coupled plasma (ICP) emission spectrometers has become standard practice in machine condition monitoring programs to determine elemental content. Unfortunately, both of these techniques become less responsive to particles as they increase in size. To overcome this limitation, several complementary methods and analytical techniques to detect large particles in used oil have been applied, including acid digestion, ferrography, and X-ray analysis. Unfortunately, these techniques are not practical or economical to implement in a high sample throughput machine condition-monitoring program. One technique that has demonstrated success as a complementary method for detecting large particles is rotrode filter spectroscopy (RFS). RFS extends the capability of rotating disc electrode (RDE) spectrometers to detect particles greater than 10 μm in size.
Analysis of Fuels, Lubricants, and Greases Using X-ray Fluorescence Spectrometry
Authors: Wolska J , Vrebos B , Brouwer P
Published: April 2008

X-ray spectrometry (XRF) is a versatile instrumental method for elemental analysis in a wide variety of materials. The performance of three different XRF systems will be compared: a high power wavelength dispersive x-ray spectrometer (WDXRF), a low-power WDXRF, and a bench-top energy dispersive instrument (EDXRF).

The data obtained show quite clearly the large difference in sensitivities between instruments. This translates into varying lower limits of detection (LLD) or quantification and sample throughput. For quantitative analysis well above the LLD, the accuracy of the results obtained on the different instruments is similar, or — for practical purposes of quality control in many applications — the differences in accuracy between the different instruments can be considered insignificant.

Most of the applications and methods developed by a variety of laboratories and regulatory organizations are applicable to specimens of a specified nature and matrix. Some of the more versatile procedures include a method to account for differences in matrix between standard reference materials and unknowns. One of the effects that is usually neglected in this case is the wedge effect, which is caused by the fact that the volume that is excited by the beam and the volume from which characteristic radiation can be observed are not the same and vary (for a given spectrometer system) depending upon the density and the quantity of the sample. This effect will be illustrated and discussed.
Rapid Determination of Suifur in Liquid Hydrocarbons for At-Line Process Applications Using Combustion/Oxidation and UV-Fluorescence Detection
Authors: Tarkanic S , Crnko J
Published: April 2008

With the reduction in sulfur levels in gasoline and diesel products, it is necessary to have a method available which can precisely and accurately measure the very low levels of sulfur in these fuels. ASTM test method D 5453, Sulfur by Combustion and Ultraviolet Fluorescence (UVF), is a laboratory-based technology that has been widely used in the industry for such purposes for more than a decade. An on-line/at-process version of this technique is described which can complete a fast analysis in less than one minute. Thus, near real-time data can be obtained when refineries and terminals need to make rapid determinations of sulfur levels for process control and pipeline distribution decisions involving the new generation “clean” hydrocarbon fuels. Particularly discussed is the advantage gained for decision making involving detection of transport boundaries and related custody transfer issues.
Various Aspects of Sodium Bentonite Testing
Authors: Olsta JT , Chung JH , Daniel DE
Published: April 2008

Sodium bentonite samples were obtained from seven bentonite mining pit stockpiles. Swell index, fluid loss and hydraulic conductivity testing of the sodium bentonite was performed at two different laboratories. The major objectives of the study were: • To determine the correlation, if any, between swell index, fluid loss and hydraulic conductivity. • To examine the sensitivity of swell index (ASTM D 5890) to variations in the test procedures.

There was a poor correlation between swell index and hydraulic conductivity. There was a good correlation between fluid loss and hydraulic conductivity. A swell index ⩾19 mL and fluid loss ⩽16 mL appeared sufficient to yield a hydraulic conductivity of 5 × 10-9 cm/sec at 5 psi confining pressure.

Swell index testing was performed with varying the number of scoops of bentonite dispensed into a graduated cylinder and with three different types of reagent water (distilled/deionized, deionized and tap water).
Quality Requirements for Bentonite in Geosynthetic Clay Liners and the Validity of Test Methods
Authors: von Maubeuge K , Egloffstein T
Published: April 2008

GCLs are primarily used to seal against water, because its very low permeability property. This very good sealing performance is caused by bentonite as sealing material, which is interspersed between two geotextiles as an approximately 10 mm thin layer of powder or granulate. The objective of performance tests of new bentonites in GCLs, is primarily to investigate how low the water permeability of the bentonite is, after its processing into a pulverised or granulate form, as it is required for their use in GCLs. The production of a test GCL for the purpose of performance testing, is very costly. Mainly due to economical reasons, producers of bentonites and GCLs are anxious to be able to predict the permeability by use of simpler test methods. The laboratory tests for bentonites commonly applied are methylene blue test, the fluid loss test ASTM D 5891, and the swelling volume after ASTM D 5890. However, they are only to a limited extend suitable for this purpose. But even highly sophisticated mineralogical and chemical investigations like x-ray diffraction and ion distribution are not helpful to forecast the water permeability value in the produced GCL.
A Simple Compatibility Testing Protocol for Bentonite-Based Barrier Systems
Authors: Osicki RS , Fleming IR , Haug MD
Published: April 2008

This paper investigates macroscopically observable properties of bentonite. Bentonite slurries were prepared with varying pore water chemistry, using salt solutions for which compatibility problems have been shown. Using these samples, a rapid testing protocol was developed for evaluation of compatibility. Fann viscometer and filter press testing are well-established methods to examine bentonite quality and expected permeability of bentonite based barrier systems. This paper presents new research into the use of these simple tools to examine potential alteration or compatibility problems. Bentonite slurries made using the permeant of interest can be quickly evaluated for comparison with water-hydrated slurries. These results were confirmed with permeameter tests using GCLs. The permeability from the GCLs can be compared with the relative values inferred from the filter press and viscometer testing related to the double layer thickness. The authors believe that this work suggests that a few quick and simple tests can be done to evaluate potential compatibility issues with bentonite in natural form or in prefabricated geosynthetics. For industry, this will have the advantage of a very quick and cheap test that may be carried out to evaluate compatibility issues.
Evolution of GCL Hydraulic Performance During Contact with Landfill Leachate
Authors: Norotte V , Didier G , Guyonnet D , Gaucher E
Published: April 2008

In France, geosynthetic clay liners (GCLs) can be used under certain conditions within liner systems for waste containment. But there still remains a lot to learn regarding the potential modifications undergone by GCLs during prolonged contact with landfill leachate. In 2001, the French Environmental Agency (ADEME) initiated the LIXAR research program aimed at examining, at different scales of observation and for different experimental conditions, the modifications undergone by GCLs during prolonged contact with leachate. This paper focuses on the permeability-diffusion tests performed as part of this research program. Two types of needle-punched GCLs, a natural sodium bentonite GCL and a sodium-activated calcium bentonite GCL, were put in contact with three types of fluids in oedopermeameter cells. Contact duration was between 4 and 6 months. Results provide information regarding the relative performance of the two GCLs and the influence of the pre-hydration and percolation fluids.
Comparing GCL Performance Using Rigid Versus Flexible Wall Permeameters
Authors: Koerner GR
Published: April 2008

Geosynthetic clay liners consist of a layer of bentonite supported by various types of geosynthetics to form a composite material. Their primary function is to serve as liners for environmental, geotechnical and transportation applications. These materials are conformance tested as well as designed based upon their hydraulic conductivity. There are currently two different permeability tests used to measure the permeability of these materials. They are rigid and flexible wall variations of ASTM D5887 entitled Test Method for Measurement of Index Flux through Saturated Geosynthetic Clay Liner Specimens Using Flexible Wall Permeameter. It is the intent of this paper to illustrate how results are influenced by different equipment. This issue is relevant because it appears that many European and Asian testing laboratories are tending toward rigid walled testing, whereas laboratories in the USA are testing via flexible permeameters.
Methods for Improving the Efficiency of Alpine Ski Equipment Rental Operations
Authors: Ettlinger CF , Shealy J , Johnson RJ
Published: April 2008

The objective of this study was to develop principles and practices which could improve the efficiency and reliability of alpine ski equipment rental facilities operating in compliance with ASTM or ISO rental standards.

Tests were conducted using a commercially available device to measure the release moments of boot/binding combinations, with contact areas between boot and binding alternately in clean and lubricated conditions. Bindings were also tested in combination with a test sole adjustable for length. The study provided a measure of the variability of the components of the release system and an estimate of the system variability experienced by rental facilities using various inspection, maintenance, and dispatch procedures. It also produced guidelines for reducing the need for applying correction factors to the release indicator scales of bindings in the rental inventory.

Among 60 boot/binding combinations the study found that the difference between clean and lubricated tests ranged from 0 % to 34 % with an overall average difference of 7 %, half that observed twenty years ago. The difference in tests comparing actual boots in a lubricated condition with a test sole of the same length in a lubricated condition ranged from +3 Nm to -3 Nm with a mean and standard deviation of less than 1 Nm, a fraction of differences noted in years past. However, release value selection tables currently in common use do not accurately reflect the relationship between boot sole length, release indicator value, and the target release torque. The study found the indicator value displayed in 64 % of the most commonly used cells in these charts varied from the optimal by release indicator increments ranging from -0.5 to +2.5.

The release characteristics of modern alpine rental boot/binding combinations are more predictable and reliable than ten or twenty years ago. However, inspection, maintenance, and dispatch procedures currently in use do not take full advantage of these capabilities. A simple procedure exists for the routine documentation of boot/binding compatibility so that rental procedures can be updated to reflect the true characteristics of contemporary rental products and thereby minimize the potential for time-consuming correction procedures and improve the release retention performance of equipment dispatched to the rental customer.
Injury Rates and Injury Types in Alpine Skiing, Telemarking, and Snowboarding
Authors: Ekeland A , Sulheim S , Rødven A
Published: April 2008

A central ski patrol-based registration of skiing and snowboarding injuries was performed by the Norwegian Ski Lift Association during the winter seasons 2000/2001 and 2001/2002. A control material of 3002 randomly sampled uninjured skiers was collected from the same ski resorts throughout the 2001–2002 season.

6138 injured skiers/snowboarders and 4 167 476 skier/snowboarder days were recorded during the two seasons, giving an injury rate of 1.5 injured per 1000 skier/snowboarder days. Most of the injuries occurred during alpine skiing (49 %) and snowboarding (45 %), whereas telemark skiing accounted for 6 % of the injuries. The injury rate for snowboarders (2.3 injuries per 1000 skier days) was significantly higher than that of alpine skiers (1.1) and telemarkers (0.7) (P < 0.001). Wrist injuries were common among injured snowboarders (26 %) compared to only 4 % for alpine and telemark skiers (P < 0.001). Snowboarders also suffered more arm and back injuries than alpine skiers and telemarkers (P < 0.001). The knee was the main injury location in alpine skiers (28 %) compared to 13 % among telemarkers and only 6 % among snowboarders (P < 0.001), but the percentage of knee injuries was almost twice as high for females compared to males in alpine skiers and snowboarders (P < 0.001).

As percent of all injuries injured snowboarders suffered more fractures (33 %) than alpine (20 %) and telemark skiers (19 %) (P < 0.001), but fracture of the lower leg was uncommon among snowboarders (1 %) and telemarkers (3 %) compared to alpine skiers (6 %) (P < 0.001). Lower leg fractures accounted for 3 % of the injured alpine skiers 20 years and older compared to 5 % for adolescents aged 13–19 years and 17 % for children 12 years and younger ( P < 0.001 ).

Beginners had an injury rate 3 times that of expert skiers/snowboarders (P < 0.001), and use of a protective helmet reduced the injury rate P < 0.001).

In conclusion, snowboarders had a higher injury rate then alpine skiers and telemarkers. Beginners had an injury rate 3 times that of experts, and use of protective helmet reduced the injury rate. Injured alpine skiers were most prone to knee injuries, and lower leg fractures were still a common injury in children. Injured snowboarders were most prone to suffer wrist, arm, and back injuries. The percentage of knee injuries among females was almost twice that of males in alpine skiers and snowboarders.
Winter Sports in an Indoor Facility—Accident and Injury Trends
Authors: Richter S , Jendrusch G , Henke H , Hermichen HG , Heck H
Published: April 2008

Along with the increasing popularity of indoor winter sport activities, the need for specific investigations with respect to injury prevention is growing This statement was the background for a one-year study in which all sports injuries/accidents reported at the indoor artificial ski slope in Neuss (Germany) were documented and evaluated by way of an accident protocol. Injuries requiring medical attention or treatment were documented in the casualty department and injured persons were interviewed by a telephone survey regarding cause, type degree, and possible consequences of their injury. A total of 372 skiing accidents were reported, 64.5 % concerning men, 35.5 % women. While the majority of ski hall visitors are skiers (57.9 %) compared to snowboarders (40.1 %, tire-tubing or others: 2.0 %), more accidents happened to snowboarders (55.6 %) than to skiers (33.3 %; tubing: 3.8 %, others: 1.1 %, not known 6.2 %). Winter sport beginners account for the largest group of accidents victims (> 40 %).Snowboarders seem to suffer a particular risk since they prefer to use the very challenging funpark section of the indoor facility, which is provoking more dangerous situations leading to accidents as a consequence.
Skiboard Injuries—A Three-Year Comparison with Alpine Skiing
Authors: Langran M
Published: April 2008

Skiboarding is a relatively new snow sport that has increased in popularity in Scotland. All skiboard and alpine ski injuries over a three-year period at ski areas in Scotland were recorded and comparative data collected from uninjured skiboarders. 136 skiboard and 1362 alpine ski injuries were recorded, as well as data from 174 uninjured skiboarders. The profile of a typical skiboarder was a young male with little experience of the sport. Compared to alpine skiing, skiboarding was associated with a higher overall risk of injury and the highest fracture rate of any snow sport reported to date. Compared to alpine skiers, skiboarders sustained more injuries to the lower limb and higher rates of lower leg fractures. The nonrelease nature of a skiboard binding appears to be a major factor in the pattern of injuries seen on skiboards. Attention should be directed towards the development of an appropriate release binding mechanism for skiboards.
Exploratory Test of 288°C Radiation Resistance of Two USSR-Produced Reactor Pressure Vessel Steels
Authors: Hawthorne JR , Sokolov MA , Server WL
Published: April 2008

The effects of 288°C (550°F) irradiation to 1.0 × 1019 n/cm2, E > 1 MeV, on the Charpy V-notch ductilities of two USSR-produced forging materials were determined experimentally. The materials were provided by the Kurchatov Institute under the umbrella of a joint USA-USSR agreement and represent the Cr-Mo-V forgings employed in the construction of USSR light-water VVER-440 reactor pressure vessels (RPVs) before and after 1980, respectively. The primary difference between the two materials is phosphorus content (0.019% vs. 0.007% P) consistent with their respective USSR Steel Specifications 15Kh2MFA and 15Kh2MFA-A. Specimens for post-irradiation property determinations were irradiated in the Ford Nuclear Reactor in a controlled-temperature assembly at an average fluence rate of 5.6 × 1012 n/cm2-s, E > 1 MeV. The post-irradiation Charpy V-notch 41 J (30 ft-lb) transition temperature elevation for the material representing pre-1980 RPVs was 31°C (55°F). This elevation was accompanied by a 27% reduction in Charpy V-notch upper-shelf energy level. for the material representing the post-1980 RPVs, the transition temperature elevation was ≤ 8°C (15°F); the concomitant post-irradiation reduction of upper-shelf energy was not established.

The observed transition temperature elevations are considerably less than the elevations predicted by NRC Regulatory Guide 1.99, Rev. 2. The converse is true for the reduction in upper-shelf energy level found for the pre-1980 RPV construction material. A higher fluence test is required for full qualification of the radiation resistance capabilities of the materials.
Analysis of Irradiation Data for A302B and A533B Correlation Monitor Materials
Authors: Wang JA
Published: April 2008

The results of Charpy V-notch impact tests for A302B and A533B-1 Correlation Monitor Materials (CMM) listed in the surveillance power reactor database (PR-EDB) and material test reactor database (TR-EDB) are analyzed. The shift of the transition temperature at 30 ft-lb (T30) is considered as the primary measure of radiation embrittlement in this paper. The hyperbolic tangent fitting model and uncertainty of the fitting parameters for Charpy impact tests are presented. For the surveillance CMM data, the transition temperature shifts at 30 ft-lb (ΔT30) generally follow the predictions provided by Regulatory Guide 1.99, Revision 2, (R.G. 1.99/2) and draft E900-98. Difference in capsule temperatures is a likely explanation for large deviations from R.G. 1.99/2 and ASTM E900-98. Deviations from the R.G. 1.99/2 predictions are correlated to similar deviations for the accompanying materials in the same capsules, but large random fluctuations prevent precise quantitative determination. Significant scatter is noted in the surveillance data. The major contributions to the uncertainty of the prediction models, and the overall data scatter, are from mechanical test results, chemical analysis, difference in effective copper content resulting from the different post weld heat treatment, irradiation environments, fluence evaluation, and inhomogeneous material properties. Thus the prediction model can be improved if the above- mentioned error sources are controlled. In general, the embrittlement behavior of both the A302B and A533B-1 plate materials is similar. There is evidence for a flux effect in the CMM data irradiated in test reactors; thus its implication for power reactor surveillance programs deserves special attention.
Fracture Toughness of the Ni-Modified A302-B Plate of the BR3 Reactor Pressure Vessel
Authors: Chaouadi R , Fabry A , van Walle E , Van de Velde J
Published: April 2008

The present paper aims to compare regulatory predictions of fracture toughness to direct measurements using precracked Charpy specimens tested in three-point bending. Trepans were extracted from the vessel of the BR3 reactor in order to perform fracture toughness tests in addition to Charpy impact and tensile testing. This vessel was successfully wet-annealed at 343°C during 1 week after a maximum neutron fluence of 3.3 1019 n/cm2. The reactor is presently under decommissioning after a maximum neutron fluence of 4.0 1019 n/cm2. The trepans (base metal and weld) were taken from two regions: vessel mid-plane and nozzle elevation (no neutrons, negligible thermal aging). Here, the base metal (Ni-modified A-302 grade B) is investigated: Tensile, Charpy impact and fracture toughness tests were performed at thickness ranging from 1/4T to 1/2T.

The determination of the reference temperature, T0, is performed according to the ASTM E1921 standard.

It is found that the 41J-shift of the Charpy impact transition curve is similar to the T0-shift of the master curve: ΔT41J= 96°C and ΔT0= 115°C. This is an important result as current regulation is based on the 41J-shift. This regulation indexes the ASME fracture toughness curve to the initial RTNDT for the baseline condition and is increased by the 41J-energy shift for the irradiated condition. This results in an over-conservatism of about 40°C. It is found also that the T41J and T0 shifts fall within the regulatory predictive bounds based on the chemistry factor (Cu and Ni-content) and neutron fluence.
Irradiation Damage Structure in VVER-440 Steels after Irradiation at Different Temperatures and Post-Irradiation Annealing
Authors: Grosse M , Böhmert J
Published: April 2008

Neutron irradiation of the VVER-440-type reactor pressure vessel steel 15Kh2MFA at lower temperature causes an increase of the content of point defects in the iron lattice. The ratio between the magnetic and nuclear scattering of these point defects shows that not only vacancies are formed but also the number of foreign atoms in solution is increased. Additionally, small precipitates grow. These precipitates are smaller and have a weaker thermal stability than the precipitates grown in this steel after neutron irradiation at service temperature. In some cases the number of precipitates which can be found in the unirradiated state decreases significantly by irradiation at 60°C. Annealing at 475°C/1h provokes coarsening of the precipitates and re-dissolution of the precipitates formed by irradiation at lower temperature.
Irradiation, Annealing, and Reirradiation Effects on American and Russian Reactor Pressure Vessel Steels
Authors: Sokolov MA , Chernobaeva AA , Nanstad RK , Nikolaev YA , Korolev YN
Published: April 2008

One of the options to mitigate the effects of irradiation on reactor pressure vessels (RPVs) is to thermally anneal them to restore the toughness properties that have been degraded by neutron irradiation. Even though a postirradiation anneal may be deemed successful, a critical aspect of continued RPV operation is the rate of embrittlement upon reirradiation. There are insufficient data available to allow for verification of available models of reirradiation embrittlement or for the development of a reliable predictive methodology. This is especially true in the case of fracture toughness data. Under the U.S.-Russia Joint Coordinating Committee for Civilian Nuclear Reactor Safety (JCCCNRS), Working Group 3 on Radiation Embrittlement, Structural Integrity, and Life Extension of Reactor Vessels and Supports agreed to conduct a comparative study of annealing and reirradiation effects on RPV steels. The Working Group agreed that each side would irradiate, anneal, reirradiate (if feasible), and test two materials of the other. Charpy V-notch (CVN) and tensile specimens were included. Oak Ridge National Laboratory (ORNL) conducted such a program (irradiation and annealing, including static fracture toughness) with two weld metals representative of VVER-440 and VVER-1000 RPVs, while the Russian Research Center-Kurchatov Institute (RRC-KI) conducted a program (irradiation, annealing, reirradiation, and reannealing) with Heavy-Section Steel Technology (HSST) Program Plate 02 and Heavy-Section Steel Irradiation (HSSI) Program Weld 73W. The results for each material from each laboratory are compared with those from the other laboratory. The ORNL experiments with the VVER welds included irradiation to about 1 × 1019 n/cm2 (>1 MeV), while the RRC-KI experiments with the U.S. materials included irradiations from about 2 to 18 × 1019 n/cm2 (>1 MeV). In both cases, irradiations were conducted at ∼290 °C and annealing treatments were conducted at ∼454 °C. The ORNL and RRC-KI experiments have shown generally good agreement for both the Russian and U.S. steels. While recoveries of the Charpy 41-J transition temperatures were substantial in all cases, significantly less recovery of the lateral expansion and shear fracture in some cases (no recovery in one case) deserves further attention. The RRC-KI results for the U.S. steels showed reirradiation embrittlement rates which are conservative relative to the lateral shift prediction based on Charpy impact energy.
Gamma-Radiation Annealing to Mitigate Neutron-Induced Degradation of Both Model and Structural Reactor Materials
Authors: Karpukhin VI , Krasikov YA , Nikolaenko VA , Shtrombakh YI
Published: April 2008

Formation and evolution of radiation defects are determined by the irradiation conditions. Some of these conditions do not get sufficient attention. In particular, this is true for the gamma-annealing process whose role in radiation-induced effects have not been considered in detail previously. Reactor experiments have shown that volume expansion of diamond and silicon carbide depends on the γ-radiation flux value: the higher the gamma-flux, the lower is the expansion. Radiation γ-annealing was also discovered in reactor grade graphite. Analysis has shown that this phenomenon is probably operating in reactor pressure vessel materials. This phenomenon opens a new perspective of radiation effects mitigation and reactor materials life cycle management using neutron and gamma-ray intensity control.
Mechanical Properties of Four 7–9%Cr Reduced Activation Martensitic Steels after 2.5 dpa, 300°C Irradiation
Authors: van Osch E , Horsten M , Lucas GE , Odette GR
Published: April 2008

Reduced Activation Ferritic/Martensitic alloys are being developed for application in future thermonuclear fusion reactors. The behavior of the reduced activation martensitic steel F82H-mod was compared with small amounts of related alloys JLF-1, JLF-1B and ORNL-9Cr2WVTa, following irradiation in the High Flux Reactor (HFR) in Petten. Tensile, KLST-type Charpy impact and CT fracture toughness mechanical properties specimens, were neutron irradiated to a dose level of 2–3 dpa at 300°C. Results of post irradiation tensile, miniaturized charpy impact, and static fracture toughness tests are presented and interpreted in terms of irradiation hardening and irradiation induced shift of ductile to brittle transition temperature (DBTT) and reduction of upper shelf energy (USE). The observed irradiation hardening (140 – 170 MPa at 300°C) is moderate, whereas the observed radiation induced shift in DBTT is approximately 150°C for KLST-type impact test specimens for F82H. Similar observations are made for the static fracture toughness tests. For JLF-1B the irradiation hardening is one third higher than for JLF-1, and shift in DBTT for JLF-1B is almost 70% larger than for JLF-1. The difference is attributed to the tenfold larger boron content prior to irradiation.
Evaluation of Ductile-Brittle Transition Behavior of Helium-implanted Reduced Activation 9Cr-2W Martensitic Steel by Small Punch Tests
Authors: Kimura A , Morimura T , Kasada R , Matsui H , Hasegawa A , Abe K
Published: April 2008

Helium implantation was performed by cyclotron with a beam of 36MeV-α particles at temperature below 429 K using a beam energy degrader to obtain homogeneous distribution of helium in a reduced activation 9Cr-2W martensitic steel up to a concentration of 120 at.ppm. The ductile-brittle transition temperature (DBTT) was evaluated by small punch (SP) tests in which the disk specimens of 3 mm diameter with 0.22 mm thickness were deformed by bulge mode. The shift in the DBTT (SP-ΔDBTT) and the increase in Vickers hardness (ΔHv) caused by helium implantation were measured to be 26 K and 67 kg/mm2, respectively, which were estimated to be 65 K of standard CVN-ΔDBTT and 104 MPa of increase in the yield stress (Δσy) from empirical relationships between them. The enhancement of irradiation hardening by helium was never recognized and no change in the fracture mode at low temperatures was observed by the helium implantation. It is considered that the shift in the DBTT is mainly associated with irradiation hardening by displacement damage.
Irradiation Creep of Austenitic Steels Irradiated Up to High Damage Dose
Authors: Neustroev VS , Shamardin VK
Published: April 2008

The irradiation-induced creep and swelling of annealed 16Cr-15Ni-3Mo-Nb stainless steels with different contents of carbon and boron in BOR-60 at 420°C have been investigated to exposures of 100 dpa. Swelling depends on carbon content and boron. The creep rate directly depends on stress and instantaneous swelling rate. The creep-swelling oupling coefficient of austenitic steels does not appear to be very sensitive to microaddition.
Irradiation Creep and Stress-Affected Swelling in Austenitic Stainless Steel 16Cr-15Ni-3Mo-Nb-B Irradiated in the BN-350 Reactor
Authors: Porollo SI , Vorobjev AN , Konobeev YV , Budylkin NI , Mironova EG , Gamer FA
Published: April 2008

Irradiation creep and void swelling are important damage processes for stainless steels when subjected to neutron irradiation at elevated temperatures. To date, most published data of this type have been derived from steels prepared by various Western nations and Japan. This paper describes the results of an experiment involving irradiation of gas-pressurized tubes constructed from Russian niobium-stabilized austenitic steel EP-172 of type 16Cr-15Ni-3Mo-Nb doped with boron. The tubes were irradiated in the lowenrichment zone of the BN-350 fast reactor to three doses of 20, 45 and 60 dpa at temperatures in the range of 480–520°C.

It was shown that the swelling of 16Cr-15Ni-3Mo-Nb stainless steels can vary strongly with minor changes in composition. Whereas EI-847 swelled easily, boron addition and other minor changes to produce EI-172 yielded a significant reduction in swelling. In both alloys, however, the swelling increased linearly with applied stress and the irradiation creep coefficients were very similar. Applied stresses influence the void number density, but not the void size or dislocation density.
Effects of Impurity on Radiation Creep Rate of the Interstitial Solid Solutions
Authors: Lopuga AD , Pyatiletov YS
Published: April 2008

The numerical self-concerted calculation of the radiation creep rate of the interstitial solid solutions was carried out with allowance for main effects of impurity on creep rate: formation of impurity atmosphere around dislocations and voids; generation of the fixed and mobile impurity atom-intrinsic point defect complexes.
The Correlation Between Swelling and Radiation-Induced Segregation in Iron-Chromium-Nickel Alloys
Authors: Allen TR , Busby JT , Gan J , Kenik EA , Was GS
Published: April 2008

The magnitudes of both void swelling and radiation-induced segregation (RIS) in austenitic iron-chromium-nickel alloys are dependent on bulk alloy composition. In this work, the resistance to swelling from major element segregation is estimated and alloys with greater nickel enrichment and fast-developing segregation profiles are shown to be less prone to swelling. In austenitic iron-chromium-nickel alloys, the total swelling depends on the duration of the transient swelling period that precedes steady-state swelling. A longer transient swelling period leads to less overall swelling for the same irradiation dose. The duration of this transient period depends on the void nucleation rate which is determined directly by the average vacancy diffusivity and indirectly by the magnitude of the segregation to the void surface. Alloys with faster vacancy diffusion have a slower void nucleation rate, a longer transient swelling period, and less swelling. Radiation-induced segregation affects swelling by decreasing the vacancy flux to the void. Because the diffusivity of nickel via the vacancy flux is slow relative to chromium, nickel enriches and chromium depletes at void surfaces during irradiation in all austenitic iron-chromium-nickel alloys. This local composition change reduces the subsequent vacancy flux to the voids, increasing the bulk point defect recombination rate, reducing the bulk vacancy concentration, which further reduces the nucleation rate and swelling. Alloys that display the greatest amount of nickel enrichment and chromium depletion are found to be most resistant to void swelling, as predicted from both void nucleation and void growth considerations.