bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Specimen Size on Fatigue Properties of Reduced Activation Ferritic/Martensitic Steel
Authors: Hirose T , Sakasegawa H , Kohyama A , Katoh Y , Tanigawa H
Published: April 2008

Small Specimen Testing Technology (SSTT) and related remote-control testing techniques are indispensable for the effective use of the limited volumes of material testing reactors and proposed intense neutron sources. As a part of this work, a new fatigue test machine with a laser extensometer for hot-cell usage has been developed. Materials used in this work were Japanese reduced activation ferritic/martensitic steel, JLF-1 (Fe-9Cr-2W-V-Ta) and its weldment. Correlations between fatigue life characteristics and fracture mechanisms were investigated for full- and mini-sized hourglass type specimens to clarify the effect of specimen size on fatigue properties. These tests revealed that there was not significant difference in the number of cycles to failure in both specimens.
Retention of Very High Levels of Helium and Hydrogen Generated in Various Structural Alloys by 800 MeV Protons and Spallation Neutrons
Authors: Oliver BM , Garner FA , Maloy SA , Sommer WF , Ferguson PD , James MR
Published: April 2008

A series of irradiations were conducted at relatively low temperatures (<100°C) in the Los Alamos Neutron Science Center (LANSCE) as part of the test program supporting the Accelerator Production of Tritium Program sponsored by USDOE. In this irradiation campaign, a variety of candidate structural alloys were placed in various particle spectra, ranging from 800 MeV protons, to mixed energy distributions of both protons and spallation neutrons, and finally to distributions consisting primarily of high energy neutrons. At proton energies on the order of hundreds of MeV, exceptionally high levels of gas atoms are generated in all elemental constituents of typical iron-based and nickel-based structural alloys, with helium typically on the order of ∼150 appm per dpa and hydrogen at approximately an order of magnitude greater. Since both of these gases are considered to exert a negative influence on structural properties of interest, their retention after both energetic recoil loss and subsequent diffusional loss is of strong programmatic interest.

Helium is essentially immobile at all temperatures of nuclear interest, but hydrogen has some limited temperature-dependent mobility, even at <100°C. To assess the degree of generation and retention, each gas was measured in a number of highly irradiated specimens of different alloy compositions and dpa levels. The results show that helium production is relatively insensitive to composition. The retained hydrogen levels, however, are somewhat sensitive to composition, reflecting different levels of diffusional loss, but are still at rather large concentrations.

The measured helium concentrations are larger than calculated using a calculational code optimized for prediction of neutron/proton ratios in the target tungsten source rods. The use of these gas measurements to provide benchmarks for determination of gas production cross sections for typical elements that comprise common structural alloys is also examined.
The Influence of High Energy Proton Irradiation on the Corrosion of Materials
Authors: Lillard S , Gac F , Paciotti M , Ferguson P , Willcutt G , Chandler G , Daemen L
Published: April 2008

This paper presents a summary of our current efforts to characterize the realtime corrosion rates of materials during 800 MeV proton radiation at currents up to 0.4 mA. Specially designed corrosion probes, which incorporated ceramic seals, were mounted in flow tubes on a water manifold that allowed samples to be directly exposed to the proton beam at the Los Alamos Neutron Science Center. The water system that supplied the manifold provided a means for controlling water chemistry, measuring dissolved hydrogen concentration, and measuring the effects of water radiolysis and water quality on corrosion rate. Real-time corrosion rates during proton irradiation increased with average proton beam current. In addition, for any given material type, a trend in corrosion rate with probe location relative to the beam centerline was observed. These results are discussed within the context of particle type, particle flux, and energy deposition.
Molecular Dynamics Simulation of Radiation Damage Production in Cubic Silicon Carbide
Authors: Malerba L , Perlado JM , Pastor I , Diaz de la Rubia T
Published: April 2008

Silicon carbide (SiC) is a candidate material for nuclear fusion reactor blankets; hence the importance of investigating its response to irradiation. Molecular dynamics (MD) simulations are a powerful tool to study radiation-damage production from the microscopic standpoint. Results of displacement-cascade MD simulations, conducted using the Tersoff potential to describe the interatomic forces, are presented herein. The number of point-defects produced in the material by silicon- (Si) and carbon- (C) primary knock-on atoms (PKAs) of increasing energy (between 0.25 and, respectively, 8 and 4 keV) is studied systematically. By comparison with standard theoretical models, threshold-displacement-energy (TDE) values of practical usefulness for SiC are derived. The effect of irradiation temperature is also allowed for. Qualitatively, the C sublattice turns out to be more heavily damaged than the Sisublattice. The effect of the irradiation temperature becomes visible only above ≈2000 K.
Influence of the Reactor and Cyclotron Irradiation on Energy Transformation during Plastic Deformation of Metal Materials
Authors: Maksimkin OP , Gusev MN
Published: April 2008

The processes of energy dissipation and accumulation were studied during plastic deformation. In addition, the characteristics of strength and ductility were obtained for pure metals and structural materials pre-irradiated by neutrons or alternatively by alpha-particles. The temperature dependencies were obtained and analyzed for both strength and ductility characteristics and stored energy. It was found, that for the studied materials in their unirradiated and/or irradiated conditions, the stored energy increase correlates with the applied stress increase, i.e. Es∼σn, where n = 2 at early stages of deformation. Due to radiation effects the material, ability to accumulate mechanical energy decreases to a great extent with irradiating fluence increase. At the same time, heat release is increasing during deformation process.
Evaluation of Pavement Smoothness and Pay Factor Determination for the Alabama Department of Transportation
Authors: Bowman B , Ellen BP , Stroup Gardiner M
Published: April 2008

In 1989 the Alabama Department of Transportation (ALDOT) added a policy to their smoothness specification that enables payments made to paving contractors to be based on the level of smoothness. The contractor can receive a 5% bonus for above average or a 5% penalty for below average smoothness readings. The measurement of smoothness has been based on the manual extraction of data from profilograph traces based on a 0.2 blanking band and resolution of 0.05. ALDOT has determined that more than three-quarters of all the 0.1 mile segments tested since the implementation of the specification have fallen in the 5% bonus range without an improvement in pavement ride quality. This observation resulted in the decision to conduct a study to determine; 1) if the ProScan™ hardware and software could be used to provide a reliable method of reducing profilograph traces, and 2) to investigate the feasibility and consequences of different smoothness pay factors. The results of the study support the ProScan™ system as a quick, accurate, and replicable method of reducing the profilographs. In addition, it was concluded that ALDOT should change the blanking band to a width of 0.0 and should adopt a combined step and continuous function method of determining incentive pay factors. With these pay factors in place ALDOT would have paid only 96.8% of the bid price for paving projects that brought 102% pay under the old step-wise function.
The Road to Smooth Pavements in Tennessee
Authors: Jackson NM , Jubran A , Hill RE , Head GD
Published: April 2008

Pavement smoothness directly affects the dynamics of moving vehicles, impacting the rate of deterioration of the pavement and the operation and safety of vehicles and occupants. Consequently, the FHWA and many state transportation agencies have taken measures to address pavement smoothness immediately following construction. The significance of smoothness is evidenced by the preliminary recommendations for the adoption of the International Roughness Index (IRI) in the forthcoming AASHTO 2002 Pavement Design Guide.

The State of Tennessee Department of Transportation (TDOT) adopted the Mays meter for the measurement of HMA pavement smoothness in the early 1980s. At that time, Mays meter measurements of 55 to 65 inches per mile (868 to 1026 mm per km) were not uncommon on pavements throughout the state. Through the implementation of increasingly stringent, incentive-based specifications, annual Smooth Pavement Awards for top-performing contractors, and advances in paving equipment, Mays meter measurements as low as 10 inches per mile (158 mm per km) are quite common today.

This paper documents the measures taken in Tennessee over the past 20 years to improve pavement smoothness.
Modulated-Temperature Thermomechanical Measurements
Authors: Price DM
Published: April 2008

There are close analogies between DSC (which measures enthalpy changes) and thermomechanical analysis (TMA) (which measures volume or length changes). This naturally leads to the application of modulated temperature programs to TMA as a means to separate the reversible nature of thermal expansion from irreversible deformation arising from creep under the applied load or changes in dimensions due to relaxation of orientation. The effect of experimental variables and calibration are described and the application of the technique to study the glass-rubber transition and melting of polymers is discussed.
Characterization of Electrorheological Processes By Dielectric Thermal Analysis
Authors: Riga AT , Cahoon JM , Pialet JW
Published: April 2008

An Electrorheological (ER) process occurs when the viscosity of fluids with dispersed particulates is modified by the application of an electric field. The ER fluids discussed in this study are dispersions of solid polymers in low dielectric base oil, an insulating fluid. When these special composite fluids are subjected to the electric field they exhibit increased shear stresses, static yield stresses and viscosity. A mechanism for ER behavior is based on the polarization of the dispersed polymer particulates. A crucial property of the ER event is the ability of the system to respond to the applied field. For example, in semi-passive shock absorbers, the response time is crucial to commercial development.

Dielectric Thermal Analysis (DETA) can measure a polarization response in an AC electric field at isothermal temperatures or by scanning temperature techniques. A Debye Plot of Tan Delta, a ratio of dielectric loss divided by the relative permittivity, versus frequency can fix the limits of a polarization or relaxation time. The critical peak frequency in the Debye Plot is inversely related to the polarization time. The ER response time in a commercial system is directly related to the polarization time. A series of polymer types have been studied in low dielectric oil and their DETA properties are reviewed.
Environmental Management Strategies for Biodegradable Nonylphenol Ethoxylates in Agricultural Products
Authors: Mihaich EM , Naylor CG , Staples CA
Published: April 2008

Nonylphenol ethoxylates (NPEs) are surfactants used as inert ingredients in pesticides and spray adjuvants. NPEs and their biodegradation intermediates [low mole ethoxylates and ether carboxylates (NPEC)] enter the terrestrial and, to a lesser extent, the aquatic environments through these uses. Nonylphenol (NP) is the basic building block of NPEs and can be a minor biodegradate. Responding to proposed water quality limits in the United States and Canada, the Alkylphenols & Ethoxylates Research Council initiated the NPE Environmental Management Program (EMP). The program, discussed in this paper, includes the development of voluntary, risk-based water quality levels for NPE, NP, and NPEC, and monitoring of waterways to determine whether water quality guidelines are being met; it also provides technical expertise to determine appropriate control methods. The approaches used in the EMP are applicable for most organic compounds and should be an integral component of best management practices.
Influence of Age and Gender on Utilized Coefficient of Friction during Walking at Different Speeds
Authors: Burnfield JM , Powers CM
Published: April 2008

A frequently cited theory suggests that ratio of leg length and stride length (i.e., normalized stride length) can be used to predict the utilized coefficient of friction (COF) during walking. As stride length and leg length differs across persons of different ages and genders, it is probable that utilized COF values also will vary. The purpose of this study was to evaluate the influence of age and gender on utilized COF during non- slip pedestrian gait. Sixty healthy adults were divided into three groups by age (10 males and 10 females in each age group): Young (20–39 y.o.); Middle-aged (40–59 y.o.); and Senior (60–79 y.o.). Ground reaction forces (AMTI forceplate; 600 Hz.) were recorded as subjects walked at slow, medium, and fast speeds. Utilized COF throughout stance was calculated as the ratio of the resultant shear force and vertical force. When collapsed across age groups, females generated higher peak utilized COF values than males at the slow walking speed (μ = .24 vs. μ = .20), while males generated higher peak utilized COF values than females at the fast walking speed (μ = .28 vs. μ = .24). When collapsed between genders, middle-aged subjects generated higher peak utilized COF values at the medium speed than both young and senior subjects (μ = .26 vs. μ = .22 and μ = .22, respectively). At the fast speed, middle-aged subjects generated higher peak utilized COF values than senior subjects (μ = .29 vs. μ = .23). No gender or age related differences in normalized stride length were found. Normalized stride length was a significant predictor of utilized COF, however, only 18% of the variance in utilized COF values could be explained by this factor. These data suggest that while age and gender differences in utilized COF exist, the basis for these differences can not be explained by normalized stride length alone.
Assessment of Slip Severity Among Different Age Groups
Authors: Lockhart TE , Woldstad JC , Smith JL
Published: April 2008

A laboratory study utilizing new techniques for assessing slip severity was conducted to investigate the process of inadvertent slips and falls among different age groups. Forty-two subjects from three age groups (young adults, middle-aged, and the elderly) walked on a rectangular track at a self-determined pace. Without the subjects' awareness, a slippery floor surface was placed on the track over a force-measuring platform. The results indicated that elderly adults' friction demand (RCOF) was not significantly different from the young and middle-aged adults. The older adults, however, fell more often than the other age groups. Fall recovery threshold (FRT) measures indicated that younger adults were able to recover from a slip (thus preventing a fall) with higher sliding speeds and longer slip distances than older adults. Additionally, older adults' adjusted friction utilization (AFU) on the slippery floor surface was not adjusted within the dynamic friction requirements, resulting in more falls. Based on the age-related differences observed, it appears that fall-related accidents among older adults are due more to factors influencing compensation of a slip rather than gait characteristics influencing slip initiation.
A Critical Analysis of the Relationship Between Shoe-Heel Wear and Pedestrian/Walkway Slip Resistance
Authors: Kim I-J , Richard S
Published: April 2008

This study seeks to clarify issues in pedestrian/walkway slip safety by exploring in detail the relationship between shoe-heel wear and slip resistance. Importantly, this paper addresses the fact that slip resistance changes as a result of wear-generated changes in the shoe-bottom and, to a lesser extent, the test surface. Insights from this paper may provide a better way of characterizing slip resistance than the commonly used averaged coefficient-of-friction (COF) value that would be compared against single-value pedestrian-friction safety thresholds. Specifically, we have derived an alternative, systematic slip resistance measurement methodology by observing the variation of COF with changes in the friction force as a function of interface wear between a shoe heel and floor surface under dry test conditions. Surface changes of both bodies were quantified using two extreme roughness parameters: Rpm and Rvm. It was found that massive wear occurred on the shoe-heel surface from very early stages of sliding and continued until the surface layer was heavily worn out. Heel contact conditions, such as initial strike time and position, changed significantly with wear evolution and, importantly, were directly related to the displacement of the friction force. Our results clearly showed that COF is not constant with respect to shoe-heel wear and, thus, friction is a function of a given set of materials as well as environmental and wear conditions.
Comparison of Slip Resistance Measurements between Two Tribometers Using Smooth and Grooved Neolite®-Test-Liner Test Feet
Authors: Medoff H , Fleisher DH , Di Pilla S
Published: April 2008

Differences in slip resistance measurements under dry and wet conditions on the same smooth walkway surface may occur when testing with a Neolite®4-Test-Liner (NTL) test foot using the PIAST [Slip Test Mark II] and VIT [English XL] tribometers. To investigate the causes of these differences, two sets of NTL test feet (smooth and grooved) for each instrument were cut from the same piece of material. Slip-resistance measurements were made under both wet and dry conditions. The same operator was used for each tribometer, an observer monitored each test, and all testing was performed in the same room at the same time. The walkway surfaces were commercial floor materials.

On dry surfaces, the measured slip resistance using the grooved test foot was the same or lower than the results using the smooth test feet. On wet surfaces, measured slip resistance using the grooved test feet increased slightly with the VIT and significantly using the PIAST. Averaged test results showed that the use of the grooved test feet on both instruments brought the readings these devices closer to each other; using the grooved test foot, the readings generated by the PIAST and VIT were not significantly different.
Fretting Fatigue Initial Damage State to Cracking State: Observations and Analysis
Authors: Clark PN , Hoeppner DW
Published: April 2008

Interrupted fretting fatigue experiments were performed to demonstrate the capabilities of a confocal microscope related to characterizing fretting damage and to correlate that damage with cycles to failure. Fretting damage was established at stepped down levels of 100% (baseline), 80%, 60%, 40%, 20%, and 10%. The damage levels were calculated as a percentage of the total cycles to fracture for the baseline fretting fatigue specimen. The baseline or 100% specimen was subjected to axial fatigue forces and normal forces to induce a fretting situation for 100% of its life or total cycles to fracture. The baseline specimen was cycled to fracture without interruption and experienced fretting due to normal forces throughout the experiment. Other specimens were subjected to cyclic forces for their respective percentage cycles under fretting fatigue conditions (i.e. with the applied normal force). After the prescribed number of cycles was attained each specimen was removed and inspected for fretting damage and characterized utilizing a confocal microscope and a scanning electron microscope. Each specimen was then cycled to fracture or run-out without the applied normal force. A damage threshold was demonstrated for fretting damage at 60% or less for these experimental conditions. Fretting was characterized as depth of damage (wear and/or pitting) and surface cracking. A key factor was the location of the fretting damage, not necessarily the magnitude of that damage. Fretting damage located near the edge of the fretting pad contact area was more detrimental than damage near the center of the fretted area.
A Critical Assessment of Damage Parameters for Fretting Fatigue
Authors: Ciavarella M , Dini D , Demelio GP
Published: April 2008

Fretting Fatigue (FF) has been considered as fatigue in a region of stress concentration due to the contact accelerated by mechanical erosion (possibly enhanced by metal transformations and/or chemical reactions in an aggressive environment). Whether the effect of erosion is significant or not is not clear. However, recently a more precise quantification of the effect of stress concentration has been attempted (some authors have used the terminology “crack analogue” and “notch analogue”). Most practical cases are concerned with finite stress concentration, so that a “notch analogue” criterion seems more appropriate, like for example in the Hertzian FF set of experiments like those on Aluminium alloy (Al/4%Cu, HE15-TF) by Nowell in the late '80s, and (A12024) by Farris in late 90s. Application of the “notch analogue” with a simple stress concentration criterion is usually overconservative for a notch (and indeed it is for the experiments considered, although it may not in general because of mechanical erosion effect in the FF case), so that “averaging” methodologies have been proposed where unfortunately the best-fitting averaging constant turns to be not just a material constant. In fact, in the present paper the “best fitting distance” is shown to be much smaller than what expected from existing Kf criteria.
Fretting Fatigue Under Block Loading Conditions
Authors: Hooper J , Irving PE
Published: April 2008

The effect on fretting fatigue life of applying periodic overloads and two-level block loading has been investigated, and the applicability of Miners damage accumulation under fretting fatigue loading conditions has been tested. The application of single 150% overloads at given intervals had a considerable effect on life, with life extensions on the order of two being observed for overload application intervals of 102 to 104 cycles. Miner's law was unable to predict the life extensions found. Two-level block loading spectra were applied in which the single overloads were made equivalent to a high-level loading block consisting of a single cycle. The effect of increasing the number of overloads in a high-level block was investigated. It was observed that as the proportion of cycles in the high-level block was increased, the damage accumulation became dominated by the high-level loading. The effect of lower-level constant amplitude loading was to extend life and delay the damage process. A hypothesis based on the contact stress analysis and tangential force hysteresis loops has been proposed and successfully explains all of the variations in fretting fatigue life observed. Miner's law cannot be confidently applied for the loading conditions tested.
The Analysis of Fretting Fatigue Failure in Backup Roll and its Prevention
Authors: Kubota M , Odanaka H , Sakae C , Ohkomori Y , Kondo Y
Published: April 2008

In the present research, a fretting fatigue failure in a backup roll (BUR) was examined. Fretting fatigue properties of the roll material were experimentally obtained and the prevention of the fretting fatigue failure was proposed. BUR is one of the most important components in a steel making rolling mill for the control of plate thickness and flatness. The BUR was initially supported by oil film bearings. Recently, oil film bearings have been rapidly replaced by roller bearings for the purpose of high-precision rolling. After the replacements, fretting fatigue failures of BUR have begun to occur. Rotating bending fatigue tests were performed with a 40 mm diameter shrink-fit axle to evaluate the fretting fatigue strength of the BUR material and to examine the improvement of the fretting fatigue strength of the holding part of the BUR. The effects of roller machining and overhanging of the contact edge on the fretting fatigue strength were investigated. Based on the results of this study, roller machining was applied to the holding part of the BUR. Furthermore, the diameter of the holding part of the BUR was increased. No failure occurred due to fretting in the BUR for more than four years since these countermeasures were applied.
Characterization of HMA Mixtures with the Asphalt Pavement Analyzer
Authors: Mohammad L , Huang B , Cea M
Published: April 2008

The Asphalt Pavement Analyzer (APA) is a laboratory scale accelerated load wheel tester. The interest in the use of the APA has grown in recent years, especially during the implementation of the Superpave mix design procedure. Currently, this mix design procedure is based on volumetric properties and has no strength test to evaluate the mixture's susceptibility to rutting.

This paper presents the findings of a laboratory study conducted to examine the sensitivity of the Asphalt Pavement Analyzer in measuring the rut depth due to changes in aggregate type and asphalt binder type. The results of the APA were also compared to the ones obtained from axial and indirect tensile creep tests. The scope of this study included a 19-mm Superpave mix, two aggregate types (limestone and sandstone) and four binder types. The four binder types were PG 64-22, an SB polymer modified asphalt meeting PG 70-22, a gelled (chemically modified asphalt meeting PG 70-22), and a SB polymer modified asphalt meeting PG 76-22.

The test results of mixtures with different aggregates and binder types indicated that the APA was sensitive to these factors. Mixes with sandstone aggregates exhibited lower permanent deformation properties, as defined by the tests considered, than similar mixes with limestone aggregates. The ranking of the APA test results and indirect tensile creep test results was generally consistent with the ranking of the binder stiffness G*/sinδ. The APA had a fair correlation with the indirect tensile creep test results.
Aggregate Contributions to the Performance of Hot Mix Asphalt at WesTrack
Authors: Epps AL , Hand AJ , Epps JA , Sebaaly PE
Published: April 2008

Unexpected performance of coarse-graded and crushed stone mixtures when compared to fine-graded and partially crushed gravel mixtures at WesTrack led to an examination of consensus aggregate properties for all mixtures used. These properties did not explain the differences in performance, but an analysis of mixture sensitivity to asphalt content and percent passing the 0.075 mm sieve did highlight the potential for substantial changes in volumetrics in terms of air voids for coarse-graded Superpave mixtures. The rutting performance of both coarse and fine-graded mixtures was sensitive to asphalt content, with coarse-graded mixtures highly sensitive to decreases in asphalt content and both types of mixtures sensitive to increases in asphalt content. Increased variability in aggregate gradation for the coarse-graded mixture coupled with this sensitivity may explain the unexpected performance. Based on these results, a sensitivity analysis was recommended for inclusion in the Superpave mix design process. Rutting performance models also indicated that volumetrics and aggregate properties related to gradation significantly contribute to performance.
Identification of Aggregate Role in Performance of Superpave Mixtures Employing Accelerated Testing Facility
Authors: Stiady J , Galal K , Noureldin S , Hand A , White T
Published: April 2008

The role of gradation type with respect to the restricted zone, nominal maximum aggregate size (NMS), coarse aggregate type, and fine aggregate angularity (FAA) on HMA rutting performance was evaluated using the prototype scale INDOT/Purdue Accelerated Pavement Testing facility (APT).

Asphalt mixtures were designed in accordance with Superpave criteria employing two NMS (19 and 9.5 mm), two coarse aggregate types (limestone and granite), three FAA levels (39, 44, and 50), and three aggregate gradations relative to the Superpave restricted zone (above, through, and below).

Significant difference in rutting performance of 19 and 9.5 mm mixtures was not observed. Granite mixtures were more rut resistant than limestone mixtures. FAA effect was apparent when comparing mixtures with FAA of 39 against those with FAA of 44. However, mixtures incorporating very high FAA values did not perform better than those incorporating typical FAA values. Equally adequate performance was obtained with mixtures having gradations plotting above (ARZ), through (TRZ), and below (BRZ) the restricted zone.
Defining Cooperative Geospatial Projects Between Organizations
Authors: Hansen DT
Published: April 2008

Cooperative development of data between organizations is increasingly common. This can reduce the data development costs for individual organizations. It also affects the data development process and the resulting products. The U.S. Bureau of Reclamation and the U.S. Fish and Wildlife Service are jointly developing a habitat monitoring program for the Central Valley, California. The program is described in a work plan between the U.S. Fish and Wildlife Service and the U.S. Bureau of Reclamation. The overall intent of this program is to evaluate changes in land cover and habitat on a periodic basis. There are three phases for the program. Phase one covers the development of a habitat base map. Phase two identifies spectral change between the base year and the year 2000. In phase three, the cause of spectral change will be identified. At that time, changes in land cover and habitat over the period will be evaluated. During these phases, close coordination between these agencies is required to see that data products meet the needs of both agencies.

The base year for the program is 1993. During phase one, a uniform habitat base map for 1993 and a habitat classification system for the Central Valley have been adopted. The 1993 base map has been developed from the best existing land use and land cover data for that time period. Surrounding the Central Valley and overlapping much of the project area is a statewide change detection program by the California Department of Forestry and Fire Protection and the U. S. Forest Service. The habitat legend will be based on a vegetation classification system that is represented in this change detection project. The Central Valley habitat program will use many of the methods and some data developed by the statewide change detection project.

Including data collected under the statewide change detection program and use of an established habitat classification system greatly accelerated this program. However, not all habitats of interest to the U.S. Fish and Wildlife Service could be initially represented in the habitat base map. Developing the base map from multiple sources increased the amount of uncertainty in habitat labels for some areas. Addressing these issues in the data development process requires the commitment of staff. Managers and staff need to recognize that cooperative efforts will require substantial additional time for coordination during all phases of the process. With vegetation, land cover, land use data, this coordination must extend to include the statewide change detection project and other state and national efforts at standardizing classification systems.
The Response Units Concept and Its Application for the Assessment of Hydrologically Related Erosion Processes in Semiarid Catchments of Southern Africa
Authors: Flügel W-A , Märker M
Published: April 2008

Proper management of valuable land resources is of paramount importance especially in regions affected by natural hazards. The sustainable development of land resources depends on the understanding of the processes and dynamics active within the landscape. In Southern African countries water shortage and water quality issues related to soil erosion are a major problem affecting the population in rural and urban areas. Consequently, during the last decade increasing attention has been focussed especially on such issues, and an increasing number of integrated hydrological and erosion studies, including the development and application of respective integrated regionalization concepts, is reflecting this development. The present study deals with the regionalization of spatially distributed hydrological related erosion processes in the catchments of the Mkomazi river (KwaZulu-Natal, South Africa) and the Mbuluzi-river (Kingdom of Swaziland). It was carried out within the framework of an interdisciplinary EU-funded project developing an Integrated Water Resources Management System (IWRMS) in semiarid catchments of Southern Africa. Within this project the concept of “Response Units (RUs)” was applied and adapted as Erosion Response Units (ERUs) to regionalize the distribution of hydrologically induced soil erosion in space and time. ERUs are landscape model entities identifying relative homogeneous hydrological related erosion processes, thus providing a spatially distributed model structure for regionalization. The examples from Southern Africa presented in this paper discuss the methods used to delineate such Response Units integrating remote sensing and GIS techniques.
Meeting of Minds—Architect, Contractor, and Owner, The Subtle Process of Communication
Authors: Pierce WJ
Published: April 2008

The façade of any structure represents collaborative efforts by architect, owner and contractor. However, these efforts sometimes result in a less than successful project. A lack of understanding around process, individual roles and project expectations appears to be the culprit. The real question, how to change the outcome for greater success. I believe that one critically important ingredient is open and honest communication between owners, architects and contractors pertaining to project expectations, scope and final results. The architect is a pivotal partner, a first stringer with understanding of design, construction methods and processes. The architect is critical to the success of the overall project. How responsive should architects be to the owner? As a partner they should educate the owner as to best methods of project delivery, construction methods and contractors suitable to deliver a mutually satisfactory project. What role does the owner expect of the architect? Is it strictly design, project management, consulting, partnership, stakeholder, educator, employee or some combination? The owner's expectations of the architect vary by project, relationship and owners real understanding of the project. The owner and architect both require clear communications in expressing the needs and true expectations of the project. Once the owner and architect understand one another, they create a process incorporating project definition, scope, project specification and selection process toward soliciting a contractor to round out and expand the owner architect partnership. This newly formed relationship of owner, architect and contractor moves forward in a collaborative manner in which each individual contribution and success complements the overall project success. Let's examine the relationship between owner, architect and contractor relative to Exterior Building Walls in obtaining maximum efficiencies, durability and longevity by improving communications from beginning to end of the project.
“Building a Better Wall System”; The Application of ASTM E 2099 “Standard Practice for the Specification and Evaluation of Pre-Construction Laboratory Mockups of Exterior Wall Systems”
Authors: Kaskel BS , Wegener TR
Published: April 2008

ASTM subcommittee E06.55 has recently developed E 2099 “Standard Practice for the Specification and Evaluation of Pre-Construction Laboratory Mockups of Exterior Wall Systems.” This practice has been developed to standardize the process for the design, construction, and laboratory testing of full-scale pre-construction mockups. These mockups are typically considered standard practice for buildings where the exterior wall system is a custom application and for buildings where a high confidence level is desired in the performance of the exterior wall system. To date, laboratory mockups have been tested using ASTM E 283, E 330, E 331, E 547, and E 1233, as well as tests developed by other organizations. E 2099 brings these various individual tests into one coherent test program. E 2099 also provides specific recommendations for the exchange of information between the exterior wall designer, the exterior wall contractor and the test laboratory. The intended goal of such an exchange of information is to provide a mechanism for valuable lessons learned in the process of the design, construction and testing of the mockup to be carried through to the product installed on the building.
Stucco Cladding — Lessons Learned from Problematic Facades
Authors: Spagna FJ , Ruggiero SS
Published: April 2008

The authors have investigated many problematic stucco facades around the United States and have documented a number of disturbing trends in the design and installation of stucco that have compromised its reliability. These trends have led to severe system failure, including stucco cracking, leakage to the building interior, deterioration of structural components, and mold growth on building materials within the wall cavity.

This paper examines the current design basis for stucco-clad walls, which for the most part is established by accepted standards of practice within the industry, with only minimum and, in many cases, inadequate standards set by the governing building codes.

Based upon our review of codes and industry literature, and the lessons learned from case histories, we present recommendations for improving design and installation details for conventional stucco.
A Wall System that Inherently Satisfies Proposed NEHRP Seismic Design Provisions for Architectural Glass
Authors: Behr RA , Wulfert H
Published: April 2008

Proposed Year 2000 revisions to the 1997 NEHRP Recommended Provisions for the Seismic Regulations for New Buildings and Other Structures (FEMA 302) include first-generation seismic design provisions written specifically for architectural glass components. Scheduled for publication by the Federal Emergency Management Agency (FEMA) as FEMA 368 in 2001, the 2000 updates of the NEHRP Provisions will elevate the degree of design attention paid to seismic life safety issues associated with architectural glass components in exterior building wall systems.

In an independent effort, an “Earthquake-Isolated Curtain Wall System” (EICWS) has been developed and tested in the Building Envelope Research Laboratory at Penn State University. By decoupling each story level of the wall system from adjacent story levels, the EICWS has shown an inherent ability to accommodate large interstory displacements in the vertical, horizontal and out-of-plane directions without jeopardizing life safety or compromising wall system serviceability. Thus, the EICWS has demonstrated an inherent ability to satisfy and exceed, by a wide margin, the proposed seismic design provisions for architectural glass that are now being considered for adoption in the 2000 NEHRP Provisions. This paper will include a description of the newly proposed NEHRP Provisions for architectural glass and a summary of recent laboratory tests of the Earthquake-Isolated Curtain Wall System.
Temperature Uncertainties for Bare-Bead and Aspirated Thermocouple Measurements in Fire Environments
Authors: Pitts WM , Braun E , Peacock RD , Mitler HE , Johnsson EL , Reneke PA , Blevins LG
Published: April 2008

Two common approaches for correcting thermocouple readings for radiative heat transfer are aspirated thermocouples and the use of multiple bare-bead thermocouples with varying diameters. In order to characterize the effectiveness of these approaches, two types of aspirated thermocouples and combinations of bare-bead thermocouples with different diameters were used to record temperatures at multiple locations during idealized enclosure fires, and the results were compared with measurements using typical bare-bead thermocouples.

The largest uncertainties were found for thermocouples located in relatively cool regions subject to high radiative fluxes. The aspirated thermocouples measured significantly lower temperatures in the cool regions than the bare-bead thermocouples, but the errors were only reduced by 8090%. A simple model for heat transfer processes in bare-bead and aspirated thermocouples successfully predicts the experimental trends.

The multiple bare-bead thermocouples could not be used for temperature correction because significant temperature fluctuations were present with time scales comparable to the response times of the thermocouples.
Understanding The Systematic Error of a Mineral-Insulated, Metal Sheathed (MIMS) Thermocouple Attached to a Heated Flat Surface
Authors: Nakos JT
Published: April 2008

Uncertainty assessments of temperature measurements performed at Sandia National Laboratories fire test facilities typically focus on measurements using mineral-insulated, metal sheathed (MIMS), ungrounded junction, chromel-alumel (Type K) thermocouples (TCs). These TCs are used to observe the temperatures of both heat sources and test objects in hydrocarbon fuel fires and simulated fires (typically up to 1200°C). Among the sources of uncertainty, errors associated with TC installation often prove to be dominant. For example, ungrounded junction, MIMS TCs have a systematic error when mounted on a flat steel plate (a commonly used configuration) when attempting to measure the plate temperature. A (relatively simple) model of an ungrounded junction MIMS TC mounted on a flat steel plate was developed. The purpose of this model is not to correct TC readings. Rather, it is to qualitatively understand the systematic error associated with the measurement and find ways to reduce the error through more effective mounting procedures or use of different junction types (e.g., grounded junction). Experimental data showing the errors are presented, as are details of the model and model versus experimental data comparisons.
Fire Safety Test Furnace Characterization Unit
Authors: Keltner N , Nash L , Beitel J , Parker A , Welsh S , Gilda B
Published: April 2008

In standardized fire safety tests such as IMO Res. A 754 (18), ASTM E119, or ISO 834, the furnace temperature is controlled to a standard time-temperature curve [1,2]. The assumption is made that thermal exposure in these tests will be repeatable and can be described by the measured furnace temperature. The significant variations that occur in test results indicate this assumption is not well founded.

Fire safety test results are influenced by both the temperature of the furnace and by heat transfer in the furnace. The heat transfer depends not only on the furnace temperature and how it is measured but also on the design of the furnace and the test unit. In developing engineering models of fire performance and performance-based codes, there is a need to understand both aspects of thermal exposure — temperature and heat transfer.

To begin to address these problems, the U. S. Coast Guard's Research and Development Center authorized a study of furnace tests. The study documented important factors in current test methods that lead to large uncertainties in the fire safety test results.

To attempt to understand and reduce these large uncertainties, the Coast Guard authorized the development of a Furnace Characterization Unit (FCU). The FCU was built, calibrated using a special electric heater at Sandia National Laboratories, and then used to characterize temperature and heat transfer in a large, gas-fired test furnace at Underwriters Laboratories. This paper reports the results of this multi-year effort.
What Do We Know About Ski Injury Research that Relates Binding Function to Knee and Lower Leg Injuries?
Authors: Shealy JE , Ettlinger CF , Johnson RJ
Published: April 2008

This review paper presents what is generally accepted today as scientific certainty in the field of alpine skiing; it is based upon knowledge that has been published in the peer-reviewed literature, presented at scientific meetings, or from other sources such as ski trade and consumer publications.

The contents of the review come from a multitude of worldwide research, as well as from the 29-year case control study by the authors. In that case control study, the release binding system performance for controls and selected injury diagnosis groups has been evaluated under simulated loads using a device defined by the American Society for Testing and Materials (ASTM) standard F504 Standard Test Method for Measuring the Quasi-Static Release Moments of Alpine Ski Bindings, or by other test devices as defined by F1061 Specifications for Ski Binding Test Devices.

The paper concentrates on common lower extremity injuries in skiing related to the unique mechanical properties of the ski-binding-boot system. It does not address non-lower extremity injuries, such as head, neck, upper body, etc. except in the context of possible inadvertent system release resulting in injury.
Injuries in Alpine Skiers, Telemarkers and Snowboarders at Norwegian Ski Resorts
Authors: Ekeland A , 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 1998/1999 and 1999/2000.

Totals of 562 injured skiers and 41582 000 lift transports were recorded during the two seasons, giving an injury rate of 1.3 injured skier per 1000 skier days or per 10 000 lift transports. Most of the injuries occurred during alpine skiing (51%) and snowboarding (40%), whereas telemark skiing accounted for 9% of the injuries. Wrist injuries were common among injured snowboarders (27%) compared to only 4% for alpine and 3% for telemark skiers (P < 0.001). Snowboarders also suffered more arm injuries (12%) than alpine skiers (5%) and telemarkers (4%) (P < 0.001). In contrast injured telemark skiers had a higher percentage of hand injuries (14%) than alpine skiers (9%) and snowboarders (6%) (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 all three disciplines (P < 0.001).

As percent of all injuries injured snowboarders suffered more fractures (34%) than alpine (20%) and telemark skiers (18%) (P < 0.001), but fractures of the lower leg were uncommon among snowboarders (1%) and telemarkers (2%) compared to alpine skiers (7%) (P < 0.001). Lower leg fractures accounted for 3.5% of the injured alpine skiers 20 years and older compared to 5% for adolescents aged 13 – 19 years and 17% for skiers 12 years and younger (P < 0.001).

In conclusion, 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 injuries and injured telemark skiers hand injuries. The percentage of knee injuries among females was almost twice that of males in all three disciplines.