bluuebunny/crossref_metadata_2025 huggingface dataset:
Titanium Matrix Composite Durability Analyses for the Design of Airframe Structures
Authors: Harmon DM , Finefield MA , Saff CR , Harter JA
Published: March 2009

A fatigue life prediction technique is described for use with titanium matrix composite materials. Damage modes specific to this material system are discussed for unnotched and center-notched laminates. Test data for isothermal fatigue and thermomechanical fatigue specimens are compared against predictions made using the analysis method.
Modeling and Life Prediction Methodology for Titanium Matrix Composites Subjected to Mission Profiles
Authors: Mirdamadi M , Johnson WS
Published: March 2009

Titanium matrix composites (TMCs) are being evaluated as structural materials for elevated temperature applications in future generation hypersonic vehicles. In such applications, TMC components are subjected to complex thermomechanical loading profiles at various elevated temperatures. Therefore, thermomechanical fatigue (TMF) testing, using a simulated mission profile, is essential for evaluation and development of life prediction methodologies. The objective of the research presented in this paper was to evaluate the TMF response of the [0/90]2s SCS-6/TIMETAL-21S subjected to a generic hypersonic flight profile and its portions with a temperature ranging from −130 to 816°C. It was found that the composite modulus, prior to rapid degradation, had consistent values for all the profiles tested. The accumulated minimum strain was also found to be the same for all the profiles tested. A micromechanics-based analysis was used to predict the stress-strain response of the laminate and of the constituents in each ply during thermomechanical loading conditions by using only constituent properties as input. The fiber was modeled as elastic with transverse orthotropic and temperature-dependent properties. The matrix was modeled using a thermoviscoplastic constitutive relationship. In the analysis, the composite modulus degradation was assumed to result from matrix cracking and was modeled by reducing the matrix modulus. Fatigue lives of the composite subjected to the complex generic hypersonic flight profiles were well correlated using the predicted stress in 0° fibers.
Data Transfer, Necessary Interfaces, and Applications in a Modular Snow Hydrology Modeling System
Authors: Rango A , Baumgartner MF
Published: March 2009

The Alpine Snow Cover Analysis System (ASCAS) is designed for monitoring changes of the snow-cover distribution in mountainous regions as well as for the determination of snowmelt runoff and evaluation of climate change effects. The transfer of data between the different software packages (that is, image processing, geographic information system, database management system, hydrologic model, and visualization of results) is essential for operational use of ASCAS. The paper describes user-developed and commercial (modified for operational use) interfaces that must exist to enable the data exchange. It is envisioned that such a system would be useful for hydropower companies for runoff simulation and forecasting, climate change evaluations, and site characterization in cold regions.
A Change Detection Methodology for the Amazon Forest Using Multitemporal NOAA/AVHRR Data and GIS—Preliminary Results
Authors: Di Maio Mantovani AC , Setzer AW
Published: March 2009

This paper describes initial results of a methodology developed to locate new deforestation in the Amazon Tropical forest. It combines automatic classification of the Advanced Very High Resolution Radiometer (NOAA/AVHRR) satellite images and a Geographic Information System (GIS) data base. Full resolution and geometrically corrected AVHRR channel 3 (3.7 μm) images of different dates of the Amazon region are automatically compared in digital form. Places where changes in the original cover of the vegetation are detected between any two different images have their locations determined through a GIS. Initial tests in the north of the state of Mato Grosso, Brazil, are presented indicating the possibility of using AVHRR imagery operationally to detect new deforestation. Results comparing deforestation in the AVHRR channel 3 with corresponding high resolution LANDSAT-Thematic Mapper (TM) images indicated 56.5% of AVHRR correct location for 221 polygons of deforestation with different sizes. 90% of correct locations was obtained for the 50 TM polygons with deforestation greater than 3.1 km2.
Spatial Data Technologies for Environmental Management Within the Department of Energy (DOE): Issues and Applications
Authors: Albers BJ , Nalezny CL , Purdy CB , Singhroy VH
Published: March 2009

The US Department of Energy (DOE) manages the Nuclear Weapons Complex, a national network of research laboratories and production facilities. For 45 years, the Complex has supplied the US with nuclear materials for weapons and fuel. However, with the collapse of the Soviet Union and an accumulated excess of nuclear materials, production has dramatically decreased and the DOE is faced with the challenge of processing wastes and remediating environmental contamination at Complex facilities.

Spatial data technologies, particularly remote sensing systems, the Global Positioning System (GPS), and Geographic Information Systems (GIS), can aid in detecting, characterizing, and monitoring hazardous and radioactive wastes. This paper discusses the role of spatial data technologies in DOE's environmental mission and gives examples of their current application within the Complex. Specific barriers inhibiting the use of the technologies within the DOE are identified and proactive measures to address them are recommended. A principal recommendation is the development of a spatially explicit model for environmental data.
Integration of a GIS Data Set with Aerial Photography Using GPS for Control Points on the Newlands Project in Nevada
Authors: Hansen DT , Sebhat M
Published: March 2009

This paper examines issues related to the integration of data that is of a higher resolution than an existing GIS data set. It concerns a GIS data base that was created nearly ten years ago. The base data layer for several GIS themes was initially captured using coordinate values from maps at a scale of 1:62 500. This base data layer represents survey information of bearing and distance measurements. Additional features were captured from a set of aerial photography at a scale of 1:7920. GPS units will be used to capture coordinates for registration of this photography for incorporation into the existing GIS data base. At the same time, the coordinate data captured by the GPS units provide an opportunity for improving the representation in GIS of the survey information.
Basic Data Requirements for Ground-Water GIS Systems
Authors: Hall PL
Published: March 2009

Traditionally, most GIS investigations present data from surficial aquifers in a 2-D plane and neglect data from boreholes and wells because it adds a third dimension to the data. This 2-D information is useful for determining surficial geology, soils and vegetation cover, all of which influence recharge and non point ground-water contaminants from pesticides and fertilizers. Using traditional GIS systems for the development of multi-layered ground water models is cumbersome and does not adequately deal with the third (depth) dimension.

However, most input data available for ground-water investigations comes from borehole logs and water well records frequently obtained as a result of a variety used for site characterization. Because of the three-dimensional nature of these data, ground water analysis should be carried out by ground-water professionals using programs designed for this specific purpose. The resulting output can be imported into GIS systems and then used by other professionals in planning, health, agriculture, and a variety of environmental applications.
The Importance of Undergraduate, Graduate, Technical, and Applied GIS and Remote Sensing Education
Authors: Bixby RO
Published: March 2009

Advances in hardware and software technologies have resulted from the acceptance of Geographic Information Systems (GIS) in academic and applied communities and in the diversity of applications that GIS can support. The Geography Department at St. Cloud State University (SCSU) curriculum has included computer mapping (now GIS and Remote Sensing) since the mid 1970s. Establishment of the Center for Geographic Information Systems at St. Cloud State University in 1991 supported the incorporation of these technological advances resulting in a wide range of curricular changes, workshops designed for specific clientele, and the addition of a graduate program and professional applied training. The process employed to establish this initiative was developed through the cooperative effort of federal, state, and local levels of governments. In addition to the wide spectrum of undergraduate and graduate classes, as well as tailored workshops, the SCSU initiative stresses the integration of academic research and graduate programs with applied topics in GIS and remote sensing. Lastly, recommendations for certification of remote sensing and GIS professionals are discussed.
Geographical Information Systems (GIS) Application to Analyze Transportation Effects on Mineral Activities in a Developing Country
Authors: Asabere RK
Published: March 2009

Many aspects of transportation analysis for mineral development are amenable to Geographical Information Systems-based processing and the range of potential applications is enormous. However, GIS is used relatively infrequently in the transport management in developing countries, especially where mineral exploitation is concerned. In mineral-resource management, planners need to know the condition and type, as well as the availability, of any road/rail network in the area where the deposit is found. The main objectives of transport analysis in this paper is to ensure, among other things, that the products from the mine and the supplies to the mine are delivered uninterrupted. Also needed is knowledge on whether the existing road/rail network will last for the life of the proposed mine, or whether a new road or rail link needs to be constructed. If the latter is necessary, site characterization data will be needed to estimate the effects of the construction on the environment and culture. Easy labor mobility between the mine and the other parts of the country also has to be studied. In this paper, a case study involving GIS analysis of the transportation network on the decision to exploit an iron-ore deposit in Ghana is presented.
Environmental Remote Sensing of Military Exercise Areas in Germany
Authors: Kühn F , Hörig B
Published: March 2009

Large areas once used by foreign troops and the National People's Army of the former East Germany are being released for civilian or other use. Therefore it is necessary to evaluate the present state of these areas. There are numerous problems that will have to be dealt with when this land is converted to other uses, since contamination and other environmental damage resulting from decades of military use is considerable. Many kinds of environmental damage are present. Apart from the risks emanating from unexploded or buried munitions, the most common problems include contamination of the soil and ground water by petroleum products and other hazardous substances, impairment of the vegetation, destruction of the natural soil horizons and erosion damage.

A combination of remote sensing and geochemical techniques was applied for site characterization during the course of investigations in a military training area. Satellite and airborne remote sensing data were evaluated, followed by groundchecks. The field studies included spectroradiometric measurements to determine the reflection properties of contaminated soil and vegetation as well as collection and analysis of soil and ground water samples to verify the results of remote sensing data.

This paper presents an overview of the evaluation of aerial photographs and satellite data, results of geochemical investigations, and discusses the combined application of remote sensing techniques and traditional investigation methods for this type of site characterization.
Integrating an Object-Oriented GIS in a Geohydrological Information System
Authors: Deckers F , van den Hoven V
Published: March 2009

The throughput and quality of work of the geohydrologist can substantially be increased through the introduction of a geohydrological information system. This is primarily a result of the fact that these systems integrate the different types of geohydrological data with tools for processing and analysis into one seamless working environment. Site characterization studies, during which information of many different origins has to be evaluated and combined, will benefit in particular from the use of such an integrated system. Due to the spatial character of geohydrological data and processing, the incorporation of a GIS into the geohydrological information system becomes a prerequisite. However, the integrated character of such systems will impose specific demands on the extensibility of any candidate GIS. The application of object-oriented principles to GIS improves their extensibility and allows for an almost seamless integration with geohydrological applications. This paper demonstrates how object-oriented concepts can be used to extend a GIS beyond its standard functional domain.
Interpreting the ASTM “Content Standard for Digital Geospatial Metadata”
Authors: Nebert DD
Published: March 2009

ASTM and the Federal Geographic Data Committee have developed a content standard for spatial metadata to facilitate documentation, discovery, and retrieval of digital spatial data using vendor-independent terminology. Spatial metadata elements are identifiable quality and content characteristics of a data set that can be tied to a geographic location or area. Several Office of Management and Budget Circulars and initiatives have been issued that specify improved cataloguing of and accessibility to federal data holdings. An Executive Order further requires the use of the metadata content standard to document digital spatial data sets. Collection and reporting of spatial metadata for field investigations performed for the federal government is an anticipated requirement. This paper provides an overview of the draft spatial metadata content standard and a description of how the standard could be applied to investigations collecting spatially-referenced field data.
Application of Content Standards for Digital Geospatial Metadata to Laboratory Data and the Site Characterization Process
Authors: Hansen DT
Published: March 2009

This paper examines sources of supporting information for data that is collected in a monitoring program were samples are collected repetitively to detect change in some parameter over time. The development of a monitoring program goes through several steps, including site characterization, site selection, sampling, and analysis. This process involves the evaluation and development of a large amount of information, which generally has not accompanied the reported tabular data. The lack of this information has often limited the application and use of the tabular data.

GIS is a valuable tool for analyzing data collected in monitoring programs with other spatial themes. To support the transfer and use of spatial data, the Federal government has adopted content standards for digital geospatial metadata. The intent of these standards is to provide sufficient information for the application and use of a spatial data set.

We have developed large sets of that have been underused frequently because the information about this data was either not available or too insufficient to make a decision on the usefulness of the data. In part, this is because of the design of the data systems used to store the reported data values. Additional notes, site descriptions, and comments on a particular parameter were often abbreviated for storage with the tabular data. Retrievals of the data have not identified the associated quality control/ quality assurance documents. Additional information describing the sampling site and sampling procedure were not associated with the sampling data.

With the systems and software tools that are currently available, all appropriate information about a sampling program can be available to the user. This information can be associated with the data regardless of the data format. This paper examines the content of information that should be available to document a long-term monitoring program addressing agricultural drainage issues in the San Joaquin Valley of California. This monitoring program is attempting to identify changes in the concentration of selected constituents in drainage water, surface streams, and wildlife on the western side of the San Joaquin Valley.
Probabilistic Composite Design
Authors: Chamis CC
Published: March 2009

Probabilistic composite design is described in terms of a computational simulation. This simulation tracks probabilistically the composite design evolution from constituent materials, fabrication process, through composite mechanics and structural components. Comparisons with experimental data are provided to illustrate selection of probabilistic design allowables, test methods/specimen guidelines, and identification of in situ versus pristine strength. For example, results show that: in situ fiber tensile strength is 90% of its pristine strength; flat-wise long-tapered specimens are most suitable for setting ply tensile strength allowables; a composite radome can be designed with a reliability of 0.999999; and laminate fatigue exhibits wide-spread scatter at 90% cyclic-stress to static-strength ratios.
Durability and Damage Tolerance: Testing, Simulation, and Other Virtual Realities
Authors: Reifsnider KL
Published: March 2009

Durability and damage tolerance are engineering definitions of phenomenological behavior. We talk about them in terms of the life and remaining strength of engineering materials and components, generally as design criteria. Hence, there is a need to associate “testing and design” in this context. But measurements of life and remaining strength are, indeed, only phenomenological; many different sets of conditions and circumstances can produce the same remaining strength and life. In that sense, such data are “virtual reality,” i.e., they are related to the fundamental physics and mechanics that define them only through interpretations. Mechanistic models are used for such interpretations, and computer-based simulations are convenient ways to combine such models to estimate durability and damage tolerance. Such simulations are also “virtual realities,” of course. This paper will address the question of how to construct mechanistic models and related experiments that provide an interpretative link between the fundamental mechanical, chemical, kinetic, and thermodynamic processes that control the long-term behavior of such materials and the remaining strength and life that defines durability and damage tolerance. Comparisons of computer simulations with experimental data will be the basis for the discussion.
Characterizing Static and Fatigue Interlaminar Fracture Behavior of a First Generation Graphite/Epoxy Composite
Authors: König M , Krüger R , Kussmaul K , von Alberti M , Gädke M
Published: March 2009

The characterization of interlaminar fracture—with the goal to obtain a database that can be used in design—is demonstrated for a first generation graphite/epoxy composite widely used by European aircraft manufacturers. Critical energy release rates for Mode I and Mode II failure have been obtained from static tests using double cantilever beam, end notched flexure, and transverse crack tension specimens. An interaction criterion for the mixed mode case is formulated based on the results from mixed mode bending tests. Fatigue tests have been carried out to determine the Paris law parameters for pure Mode I, pure Mode II, and mixed mode conditions as well as threshold energy release rates that could be used as a design limit in a no-growth concept. In accordance with the static case, an interaction criterion is formulated for the crack growth rate under mixed mode conditions. Delamination progression in more complex specimens has been measured, and mixed mode energy release rates have been computed along the delamination fronts. Results lie well within the scatter band of the Paris law as obtained by the specimens employed for characterization. This confirms that the data obtained from the characterization of interlaminar fatigue growth can be applied for predictions in design.
Statistical Microbuckling Propagation Model for Compressive Strength Prediction of Fiber-Reinforced Composites
Authors: Tomblin JS , Barbero EJ
Published: March 2009

Compressive strength prediction for a fiber-reinforced composite material still remains an unresolved topic when dealing with composites in the design process. Although significant scatter is present in the experimental data, experimental test results are the only criteria on which to base design parameters. Although significant advances have been accomplished recently by various modeling techniques, only quantitative comparison with experimental data may be realized. This quantitative comparison requires the use of a semiempirical parameter into the model formulation, which is usually set as the fiber misalignment. By using a single value of the fiber misalignment within the composite, model predictions easily match the experimental data because of the extreme sensitivity of the model with respect to fiber misalignment. However, it is well known that there is not a unique value of fiber misalignment for all the fibers but rather a distribution of misalignments throughout the composite. In this paper, using the complete fiber misalignment distribution, stability theory is coupled with continuous damage mechanics to generate a model for compressive strength of continuous fiber-reinforced composites. Sample results are also presented showing the correlation of the analytical model with experimentally measured strengths.
Compressive Strength of Unidirectional Composites: Measurement and Prediction
Authors: Soutis C
Published: March 2009

The present work examines the effect of resin ductility (varied as a function of temperature) on the compressive strength of unidirectional T800/924C carbon fibre-epoxy laminates. Tests are conducted in a screw-driven machine between room temperature and 100°C. Untabbed straight-sided specimens are used in a modified Celanese test rig; conventional serrated grip faces of the Celanese jig are replaced by spark-eroded inserts to eliminate adhesively bonded tabs on the specimen ends and minimize gripping region failures. Test results show that at approximately 80°C the failure mode switches from in-plane to out-of-plane fibre microbuckling. As the test temperature increases, the shear strength/stiffness of the resin is considerably reduced; this decreases the amount of side support for the fibres and reduces the strain level at which fibre buckling occurs. Recent fracture models are used to predict the compressive strength of the T800/924C system; agreement between theory and experiment is acceptable.
A Comparison of Life Prediction Methodologies for Titanium Matrix Composites Subjected to Thermomechanical Fatigue
Authors: Calcaterra JR , Johnson WS , Neu RW
Published: March 2009

Several methodologies have been developed to predict the lives of titanium matrix composites (TMCs) subjected to thermomechanical fatigue (TMF). This paper reviews and compares five life prediction models developed at NASA-LaRC, Wright Laboratories, and Clarkson University. The models developed at NASA-LaRC and Clarkson University are based on a single parameter, the fiber stress in the load-carrying, or 0°, direction. The two other models, both developed at Wright Labs, are multi-parameter models. These can account for long-term damage, which is beyond the scope of the single-parameter models, but this benefit is offset by the additional complexity of the methodologies. Each of the methodologies was used to model data generated at NASA-LeRC, Wright Labs, and Georgia Tech for the SCS-6/Timetal 21-S material system. Viscoply, a micromechanical stress analysis code, was used to determine the constituent stress state for each test and was used for each model to maintain consistency. The predictive capabilities of the models are compared, and the ability of each model to accurately predict the responses of tests dominated by differing damage mechanisms is addressed.
Alcohol Use and Downhill Ski Injuries: A Pilot Study
Authors: Meyers AR , Perrine MW , Caetano R
Published: March 2009

This study was designed to determine (1) skiers' drinking behavior, (2) the relationship between ski injuries and alcohol use, and (3) the feasibility of field studies of alcohol consumption and skiing.

There were interviews with 389 injured and 899 randomly selected uninjured adult skiers at a northeastern U.S. resort. Interviews probed demographics; skiing abilities and experiences; assessments of sensation, thrill, and excitement seeking; interest in new experiences; opinions of alcohol's effects on ski performance; and 24-h drinking histories. Breath alcohol concentration (BAC) was measured by an evidentiary-quality device.

Participation rates were 76% injured and 86% uninjured skiers. Six percent of all skiers had BACs > 0, and 34% reported alcohol use within 24 h of interviews. Younger skiers were more likely to have drunk within 24 h of interviews. Injured skiers were more likely to report that they generally do not drink while skiing, but also were more likely to have used alcohol within 24 h of the interviews. There was no association between injury risk and BAC.

Data suggest (1) a strong relationship between alcohol use and ski injury; (2) a need for educational countermeasures, with special attention to skiers who do not normally drink when they ski, and (3) the feasibility of more conclusive field studies of ski injuries and alcohol use.
Risk of Sudden Cardiac Death During Downhill Skiing and Mountain Hiking
Authors: Burtscher M , Mittleman MA , Nachbauer W , Philadelphy M , Likar R
Published: March 2009

Previous studies demonstrated an increased risk of cardiac events, for example, sudden cardiac deaths (SCDs), during vigorous exercise. However, such events seem to be provoked particularly in people who are normally sedentary. Only a few investigations deal with SCDs during downhill skiing or have drawn comparisons with other types of mountain sports.

Therefore, we analyzed the fatalities during mountain sports in Austria from 1985 through 1993. The number of persons involved in mountain sports was compiled on the basis of a representative Austrian-wide survey taken in 1984 and in the 1989 microcensus. SCDs are defined as unexpected, nontraumatic events that lead to death within 1 h after the onset of symptoms.

In nine years (1985 to 1993), 157 SCDs occurred during downhill skiing and 361 during mountain hiking. About 90% of all SCDs were attributed to men over 34 years of age. The mountain-sport-related SCD risk to male nonmembers of mountaineering associations, over 34 years of age, was 2.2 (1.7 to 3.0) for skiers and 4.2 (3.5 to 5.1) for hikers, when compared with the SCD risk (1.0) for the entire Austrian male population (after adjustment for age and exposure time). However, a great increase in risk for skiers was observed above the age of 50. In contrast, a diminished risk was found for hikers and for skiers who practiced mountain sports more regularly. Therefore, regular physical activity may be considered the best prevention, especially for the main risk group.
Ski Binding Minimum Retention Requirements
Authors: Crawford RP , Mote CD
Published: March 2009

The goals of the study were to quantify how well weight, the product of weight and leg length, and measures of leg strength predict the minimum ski binding retention requirements (MRR) and assess how skier ability, the skiing maneuver, ankle and knee flexions, weight bearing, mean rectified electromyography (MREMG) in the thigh, and concomitant force/moment (F/M) components affect the MRR. Joint flexions at the ankle and knee, MREMG, and F/M components between the binding and the ski were measured in 36 subjects during aggressive skiing. Distributions of the maximum F/M components from run-to-run were used to conclude the MRR for each skier.

Skier weight (W) and weight multiplied by leg length (W x lk) predicted the forward bending moment at the boot top MRR with higher correlation than the varus/valgus and internal/external twisting moment at the knee MRR. The MRRs were essentially independent of skiing ability and the skiing maneuver employed. The maximum F/M components typically occurred during moderate ankle and knee flexion and weight bearing and reduced substantially during conditions of low or high ankle flexion, knee flexion, and weight bearing. The maximum internal/external twisting moments measured during skiing were a strong function of the forward/backward bending and varus/valgus moments. These results offer a basis for the design of ski bindings and binding adjustment standards that may help to reduce the incidence and severity of injuries related to binding function.
Analysis of Skiing Accidents Involving Combined Injuries to the Medial Collateral and Anterior Cruciate Ligaments
Authors: Hull ML
Published: March 2009

Two types of ligament injuries common in skiing are both isolated anterior cruciate (ACL) and medial collateral (MCL), frequently in combination with ACL. Based on research related both to ligament injury mechanics and two-mode release binding function, the purpose of this paper was to critically assess the ability of two-mode release bindings to prevent combined MCL/ACL injuries. Making this assessment entailed several steps. First the loads typically transmitted by the knee during falls in which combined injury occurred were determined. Because more than one load was transmitted, the next step was to discern which of the loads was more damaging. Finally, heel-toe type bindings were evaluated for their potential to release in response to damaging loads.

The conclusions from these steps were that combined MCL/ACL injuries typically occur in forward-twisting-type falls where the primary loads are external axial and valgus moments at the knee. Of these two loads, an external axial moment is more damaging than a valgus moment both to the MCL when the joint is intact and to the ACL when the MCL is damaged. Heel-toe type bindings offer release sensitivity to this moment. Because bindings offer the release sensitivity to protect against many combined MCL/ACL injuries, the release level of the toepiece in twist is an important factor in the prevention of these injuries.
Computer Simulation as a Tool to Investigate ACL Injuries During Landing Movements in Downhill Skiing
Authors: Gerritsen KGM , van den Bogert AJ , Nachbauer W
Published: March 2009

This paper provides a brief overview of possibilities for the use of forward dynamic musculoskeletal models as a tool to investigate anterior cruciate ligament injuries during landing movements in downhill skiing. The minimum required model components are briefly described. An example of a simulated normal landing movement is presented. The big advantage of computer simulation is that possibly dangerous modifications of equipment can be studied. The main disadvantage is that the computer model is only an approximation of the real object of study. Therefore, existing models must be subjected to more validation until their predicted anterior cruciate ligament forces can be treated with greater reliability. Trends, however, indicating the direction of changes in predicted loading are more reliable at this point.
A Novel Apparatus for Measuring the Penetration of Chemical Vapors Through Air Permeable Materials
Authors: Rajagopalan K , McCord MG , Barker RL
Published: March 2009

Air permeable chemical protective clothing materials provide protection against permeation of toxic liquids and gases, while also allowing the permeation of air and moisture vapor. Evaluating the chemical permeation resistance of air permeable materials presents a technical challenge. Therefore, a novel apparatus was developed, which was specially designed to evaluate the penetration of chemical vapors through this type of air permeable protective clothing materials. The test apparatus was developed by modification made to a device used to conduct the ASTM F739 test. The details of the apparatus are described. The advantages of the experimental approach are also discussed.
Asbestos Penetration Test System for Clothing Materials
Authors: Bradley OD , Stampfer JF , Sandoval AN , Heath CA , Cooper MH
Published: March 2009

For hazardous work such as asbestos abatement, there is a need to assess protective clothing fabrics and seam constructions to assure an adequate barrier against hazardous material.

The penetration of aerosols through fabrics usually is measured by challenging fabric samples with an aerosol stream at a constant specified airflow. To produce the specified airflow, pressure differentials across the samples often are higher than exist in a work environment. This higher airflow results in higher aerosol velocities through the fabric and, possibly, measured penetration values not representative of those actually experienced in the field. The objective of the reported work was to develop a test method that does not require these higher airflows.

We have designed and fabricated a new system that tests fabric samples under a low, constant, specified pressure differential across the samples. This differential is adjustable from tenths of a mm Water Gauge(hundredths of an inWG) to over 25-mmWG (1-inWG). The system operates at a pressure slightly lower than its surroundings. Although designed primarily for asbestos, the system is equally applicable to the testing of other aerosols by changing the aerosol generator and detector. Through simple modification of the sample holders, the test apparatus would be capable of evaluating seam and closure constructions.
Evaluation of a New Mechanical Pressure Tester for Barrier Fabrics
Authors: McCullough EA , Johnson PW
Published: March 2009

ASTM F23.40.04, Draft Test Method for the Resistance of Materials Used in Protective Clothing to Penetration by Synthetic Blood Using a Mechanical Pressure Technique, was evaluated and compared to three other barrier test methods that apply hydrostatic pressure to the liquid and fabric. The new instrument applies continuous mechanical pressure to the fabric and synthetic blood until penetration is visible, and the penetration pressure level is recorded. The barrier properties of 14 different surgical gown materials and control fabrics were measured using the new method and ASTM F 1670 and F 1671 and AATCC 127. Surgical gown materials reinforced with films, coatings, or membranes passed ASTM F 1670 and F 1671 and reached the highest pressure level attainable on the AATCC 127 and ASTM F23.40.04 tests. Single-layer and fabric reinforced gowns exhibited varying degrees of liquid resistance. The new method simulates the high mechanical pressures of short duration that occur during surgery. It deserves consideration as a standard.
A Modified Version of Proposed ASTM F23.20.05: Correlation with Human Body Experiments on Static Propensity
Authors: Gonzalez JA , Rizvi SA , Crown EM , Smy PR
Published: March 2009

A modification of the proposed ASTM Test Method for Evaluating Triboelectric (Static) Charge Generation on Protective Clothing Materials (F23.20.05) procedure has been developed to measure peak potentials and energies from a capacitor, as well as peak potentials and decay rates from specimen surfaces charged by triboelectrification. The test system simulates a clothed human body rubbing an insulated surface and touching a grounded object, generating a spark of several thousand volts.

Experiments following both the proposed ASTM method and its modification were conducted at both 0% and 20% relative humidity (RH) and room temperature. Several one- and two-layer fabric systems were tested, including combinations of aramid/PBI, aramid/carbon, aramid/FR viscose, non-FR cotton and FR cotton.

Data from both tests were regressed with peak potentials obtained during human-body experiments. At 0% RH, regression coefficients (R2) were 0.85 and 0.28 for peak potentials and charge decays from fabric surface (proposed ASTM F23.20.05), respectively. For peak potentials and energies (modified version), R2 were 0.92 and 0.86, respectively. At 20% RH, R2 were 0.86 and 0.34 for peak potentials and charge decays (proposed ASTM), respectively, and 0.94 and 0.87 for peak potentials and energies (modified ASTM), respectively. Thus, it seems that measuring the peak potentials and energies from charged fabric systems using the new device and procedure can be considered sufficient to predict with high accuracy the static propensity of protective clothing systems in real-life conditions.
A Study of New and Existing Bench Top Tests for Evaluating Fabrics for Flash Fire Protective Clothing
Authors: Torvi DA , Dale JD , Ackerman MY , Crown EM
Published: March 2009

A study of bench top tests for thermal protective fabrics was undertaken to answer questions about the interpretation of data from these tests, and to evaluate suggested modifications to existing tests. Fixed duration tests using either skin simulant or copper disk heat flux sensors may be a useful alternative to existing bench top tests. However, more work is required before fixed duration tests can be implemented. While predictions of times to third degree burns for bench top test require the use of the Henriques' burn integral, the Stoll second degree burn criterion was found to predict times to second degree burns reasonably close to predictions made using Henriques' burn integral for many bench top test exposures.

It was also found that the heat fluxes used in bench top tests may not be indicative of those in actual flash fires. Current tests which utilize a planar geometry were also found to adequately represent the heat transfer in the more complex geometry of the human body during these exposures.
Limiting Dermal Exposure of Workers to Pesticides from Contaminated Clothing
Authors: Welch L , Obendorf SK
Published: March 2009

The function of traditional clothing materials in reducing pesticide exposure is not fully understood. Most clothing research has focused on primary dermal exposure that results from direct contact with the pesticide and on barrier protective materials. This project measures the transfer of pesticide from contaminated, non-barrior clothing through excised human skin with the goal of further understanding the role of conventional workclothes in reducing worker exposure. The objective of the study was to demonstrate whether an in vitro test method can be used to screen for percutaneous absorption of pesticides transferred via clothing. Cotton denim was contaminated with radiolabeled methyl parathion. The transfer of pesticide from the fabric and subsequent transfer through skin was observed using the Franz diffusion cell. This study demonstrates that a modified Franz diffusion cell technique is a viable method for evaluating the percutaneous absorption of pesticides transferred via clothing.
Bloodborne Hazard Protective Apparel with Reasonable Comfort
Authors: Barnes CR , McCord MG , Tucker PA , Barker RL , Shalev I , Zingelmann JL
Published: March 2009

Six commercially available surgical gown materials were tested for resistance to viral penetration and for heat and moisture transfer capabilities. All the materials contained films laminated onto substrate fabrics. Two of the samples contained microporous films, while the other four contained monolithic films. The samples containing the microporous film failed to prevent passage of the virus, while those containing the monolithic film did prevent penetration. The microporous films did allow the highest level of moisture vapor permeability and comfort ratings, but the values for some of the monolithic films fabrics were comparable. In order to investigate the effect of pore size on barrier and comfort properties, polycarbonate membranes of known pore sizes were subjected to the same test methods as the fabrics. The virus was found to be withheld by membranes with a pore size of 0.05 μm.
Evaluation of the Protective Performance of Fabrics and Fabric Combinations Against Molten Iron
Authors: Mäkinen H , Laiho H , Pajunen P
Published: March 2009

The protective performance against molten metal has commonly been measured for the outer layers of garments. Heavy-weight wool melton offers the best overall protection against molten metal owing to its metal-shedding property coupled with high thermal insulation. Reflective aluminized materials, which also protect against radiant heat, have been found to give good protection against molten metal. In normal use, however, these materials have limited use because of their stiffness, tight weave, and impermeable construction. Many flame-retardant cotton fabrics also offer protection against molten iron to some degree. In this study the protective performance of fabric combinations of garment materials, for 8 hours use, was evaluated. The performance against flame spread and molten iron was measured for various flame-retardant outerlayer fabrics and fabric combinations with non-flame retardant and flame retardant underwear fabrics. With all inner layers the molten iron classification increased, regardless of whether the material was flame-retardant or not, synthetic or not. If the outer layer was thick enough, the combination passed also the flame spread test, but with thinner outer layers, hole was formed in the inner layer. The results from the laboratory tests showed that protection can be increased conciderably, from class 1 (60–120 g iron) to class 3 (over 201 g iron), if flame-retardant underwear is used under flame-retardant cotton outer fabric. The material combination is still comfortable enough for eight-hours use.
Comparison of Prototype Artificially-Cooled Chemical Protective Glove Systems
Authors: Branson DH , Simpson LS , Claypool PL , Chari V , Ruiz BM
Published: March 2009

The purpose of this research program was to design and evaluate prototype artificially-cooled gloves that enhance thermal comfort as assessed by skin temperature, sweat rate, manual dexterity and perceived comfort. Three multiple-layered glove systems were sequentially designed and tested under simulated environmental conditions in a controlled laboratory chamber. Artificial-cooling and a liner were successful in reducing skin temperature and perceived moisture-related discomfort. Manual dexterity was hampered by one liner design.
Significant Gender Differences in Alpine Skiing Injuries: A Five-Year Study
Authors: Greenwald RM , France EP , Rosenberg TD , Toelcke T
Published: March 2009

A retrospective analysis of ski injuries at a large Utah ski area was conducted to identify injury trends and to corroborate information from previous comparable studies. A total of 5360 injuries were treated at the ski area base clinic between 1989 and 1993. The overall injury rate was approximately 2.1 per 1000 skier visits. Knee injuries were the most prevelant injury type, accounting for 43% of all injuries. Significant differences with previously published literature were noted in mean and median age of injured skiers, indicating demographic differences among the injured population at ski areas. Distributional analyses of injury diagnosis broken down by sex revealed significant differences between ski area injury rates and types both overall and between men and women, and demonstrate the need for multiarea studies aimed at identifying trends associated with terrain, snow conditions, and skier demographics. A prospective study begun in 1991 will attempt to quantify the significant differences between male and female skiing injuries at this ski area and will expand to several areas in close proximity for further study.
Skiing Collision Accidents: Frequency and Types of Injuries
Authors: Burtscher M , Philadelphy M
Published: March 2009

Accidents involving collisions on a ski slope often lead to severe injuries and represent a particular problem due to the great difficulty of establishing guilt. Surveys of relative accident frequency and of the type of injury incurred by victims and causers of collisions were the goals of our investigation.

Members of the Alpine Gendarmerie recorded the skiing collision accidents in Austria from 1986 to 1991 and the authors carried out the data analyses.

Serving as a further basis for computations were the micro-census results of 1989 and the yearly figures recorded for transport of persons on cable cars and ski lifts.

From 1986 to 1991 in Austria 5743 persons were injured in collision accidents on ski slopes—most of them severely. Based on the recorded events, one of 4500 skiers was involved in a collision in 1989. The relative collision frequency between 1986 and 1991 has increased by more than 60%. The victims of collisions were injured much more frequently than the causers (93% versus 25%). The main group of collision causers consists of teenaged and young adult males. While in a “normal” skiing accident the lower extremities are the leading areas of injury, collision accidents lead frequently to multiple injuries involving mainly the head. In the group of collision victims, every second child had a head injury.

The serious consequences of such collisions are understandable with a view to the kinetic energy of the moving skier. While on a long-term basis pedagogic-didactic measures have to be implemented to prevent such accidents, on a short-term basis technical and organizational measures are more important.
Ski Field Injuries: The Snowboarders
Authors: Lamont MK
Published: March 2009

Snowboarding is a growth sport and its participants are competing with downhill skiing for a share of the piste (or ski field). The totally different style of the snowboarders, their age, and their desire to perform tricks make them an additional, at-risk group using a ski field. Because there are now a number of competing piste users, it is important to delineate injury rates from ski field rate (incorporating all people on the ski field), or skier rate—that is, those participating in downhill skiing, or snowboarders. The increase in telemark skiing—spreading from its origins in Norway—will add another dimension to the piste competition, and another subgroup of ski field injuries.

Snowboarders present different injury patterns, having almost the same incidence of leg and arm injuries, compared with downhill skiers, who sustain almost twice as many leg as arm injuries. The injured snowboarder is younger than the injured skier, and the snowboarder is more likely to be male. Regrettably, the New Zealand data do not allow an analysis of injury rates for snowboarders because the composition of the total snowboarding population is unknown.
Epidemiology of Skiing Injuries in a Large Italian Ski Resort During 1988–1992
Authors: Molinari M , Bertoldi L , Zucco P
Published: March 2009

A retrospective analysis of 6067 injuries that occurred in a large Dolomite area during the 1988–92 ski seasons is presented.

The injuries are divided into two subgroups, year and age, with adults and children showing important differences regarding injury pattern. The absolute number of injuries increased as the number skier visits increased, while the incidence of injuries decreased. Collision injuries increased in the children's group only. In the adult group, soft tissue injuries increased, due primarily to the greater number of knee sprains (46.5%), while upper extremity injuries decreased. In the children's group, fractures accounted for the majority of injuries (63%), increasing slightly for the lower leg, while head injuries represented more than 13% of total injuries.

The authors suggest the need for a greater effort in research into better materials, improved information and safety campaigns, in the physical training of skiers, in improving ski areas, in quick emergency care, and in continuous ski area patrolling.