bluuebunny/crossref_metadata_2025 huggingface dataset:
Inorganic Analytical Methods Performance and Quality Control Considerations
Authors: Aleckson KA , Fowler JW , Lee YJ
Published: December 2008

The United States Environmental Protection Agency's Contract Laboratory Program was established to produce analytical services in support of Superfund (CERCLA) site investigations and to provide legally defensible analytical results of known and documented data quality. The inorganic analytical protocol was developed for the analysis of 24 metals in aqueous and solid matrices. Methods are included in the protocol for inductively coupled argon plasma, heated graphite furnace atomic absorption, and mercury cold vapor spectroscopy. Precision, accuracy, detection limits, and other performance criteria are monitored by the Environmental Monitoring Systems Laboratory — Las Vegas. The observed performance of this protocol in the production-line analysis of thousands of samples by contractor laboratories is presented in this paper.
Dioxin Analytical Methods — General Description and Quality Control Considerations
Authors: Kleopfer RD
Published: December 2008

2,3,7,8-Tetrachlorodibenzo-p-dioxin is of unique environmental concern because of its extreme toxicity and persistency. A well-documented procedure was developed to measure parts per billion levels in soil using high resolution gas chromatography/low resolution mass spectrometry. The method utilizes isotope dilution quantitation procedures with selected ion monitoring. A comprehensive quality assurance plan was developed to evaluate and verify data quality. Modified methods, based on low resolution mass spectrometry and tandem mass spectrometry, were developed to provide high quality data on a more timely basis.
Assessment of Aquatic Effects Due to Acid Deposition
Authors: Malanchuk JL , Mundy PA , Nesse RJ , Bennett DA
Published: December 2008

Increased concern over the impact of acid deposition on natural resources has caused the proliferation of substantial research in the area of effects. Often overlooked is the synthesis of this vast body of information into a coherent picture to be used for assessment and policy analysis. Relationships among research projects frequently are poorly defined or lacking, and problems of spatial and temporal resolution are abundant. The acquisition and use of historical data, for example, water quality and fish stocking data, to determine trends over time is problematical. Assessments of aquatic effects will be made in 1985, 1987, and 1989 under the National Acid Precipitation Assessment Program. A procedure is presented which attempts to organize existing information over space and time. Problems are highlighted and information needs made apparent.
The Effects of Short-Term and Continuous Experimental Acidification on Biomass and Productivity of Running Water Periphytic Algae
Authors: Parent L , Allard M , Planas D , Moreau G
Published: December 2008

The effect of short-term and continuous acidification on the primary production and biomass of periphyton was studied in seminatural conditions using an experimental device simulating streams ecosystems. After allowing periphytic algae to colonize unglazed ceramic tiles for 4 to 6 weeks under natural conditions, the pH of the water was lowered with sulfuric acid (H2SO4) from 6.5 to 6.7 to 4 to 4.6 for short periods (12 to 72 h) or long periods (continuous acidification, 84 days). During short-term acidification, in all the experiments but one, there was a significant increase (up to 2.6 times as compared to the control) of the primary production and specific activity in the first 12 h, followed by a significant decrease and slow recovery from 48 h until the end of the experiment. If acidification is continuous, primary production and specific activity are significantly higher (between 10 to 15 times that of the control) in acidified channels, either with or without aluminum, by Day 33 and until the end. Biomass stayed constant or decreased in short-term acidification and increased (from 10 to 15 times) in continuous acidification.
Relationships of Spatial Gradients of Primary Production, Buffering Capacity, and Hydrology in Turkey Lakes Watershed
Authors: Lam DCL , Bobba AG , Jeffries DS , Kelso JMR
Published: December 2008

The carbon uptake rate of phytoplankton was found to increase from poorly buffered, headwater lakes to better buffered, downstream lakes in the Turkey Lakes Watershed near Sault Ste. Marie, Ontario, Canada. While the nutrient, sunlight, and temperature conditions remained fairly uniform, the pH, alkalinity, and dissolved inorganic carbon concentration increased in a similar manner as the primary production. Discussions are presented on the relationships of these spatial gradients and their probable causes in such a small watershed (area = 10.5 km2). In particular, results from a hydrological model show that more groundwater flowed into downstream lakes than headwater lakes. The greater soil-water contact time and the higher concentration of calcium carbonate (CaCO3) present in the till at low-lying areas cause the introduction of relatively greater quantities of Ca2+ and alkalinity into the downstream lakes. Thus, the development of acidification-eutrophication models must incorporate the physical, chemical, and biological processes for both soil and water.
Influence of Alkali-Silica Reaction on the Engineering Properties of Concrete
Authors: Swamy RN , Al-Asali MM
Published: December 2008

Tests were conducted to quantify the effect of alkali-silica reaction on the properties of concrete. Two reactive aggregates, Beltane opal and an amorphous fused silica, were used to simulate the reaction in the laboratory. At 0.1% expansion, concrete containing 5.2 kg/m3 equivalent sodium oxide showed a loss of 12% compressive strength but 50% tensile strength. The compressive strength was not found to be a good indicator of alkali-silica reaction, but the modulus of rupture test proved to be a sensitive and reliable test to identify the progress of the reaction. Dynamic modulus and pulse velocity also appear to be good indicators of alkali-silica reaction. The tests suggest that fused silica is an ideal reactive aggregate to simulate expansion due to alkali-silica reaction, and that it provides an effective means of determining the deterioration in concrete properties and in evaluating mineral admixtures to control expansion.
Ignition of Metals and Alloys by High-Velocity Particles
Authors: Benz FJ , Williams RE , Armstrong D
Published: December 2008

The ignition of metals and alloys by impacting high-velocity particles in gaseous oxygen was investigated. A convergent/divergent nozzle was used to accelerate the flowing oxygen, which in-turn accelerated the particles to velocities greater than 305 m/s (1000 ft/s). The test sample (target) was placed at the end of the chamber in the flow path.

Aluminum 6061, Type 316 stainless steel, Type 304 stainless steel, and Inconel 718 were ignited with 1600-μm aluminum 2017 particles at elevated temperatures and pressures whereas Monel 400 could not be ignited. The ignition susceptibility of metals and alloys appeared to increase as the inlet pressure, sample temperature, and particle size were increased. Type 304 stainless steel particles required more extreme conditions for ignition of materials than similar sized aluminum particles. The results indicated that ignition and subsequent burning of the particles were required for ignition of the target materials with the possible exception of Aluminum 6061.
Comparative Results of Autogenous Ignition Temperature Measurements by ASTM G 72 and Pressurized Scanning Calorimetry in Gaseous Oxygen
Authors: Bryan CJ , Lowrie R
Published: December 2008

The autogenous ignition temperature of four materials was determined by ASTM (G 72) and pressurized differential scanning calorimetry at 0.68-, 3.4-, and 6.8-MPa oxygen pressure. All four materials were found to ignite at lower temperatures in the ASTM method. The four materials evaluated in this program were Neoprene®, Vespel SP-21®, Fluorel E-2160®, and nylon 6/6.
Behavior of Fire Spreading Along High-Temperature Mild Steel and Aluminum Cylinders in Oxygen
Authors: Sato J , Hirano T
Published: December 2008

Effects of the metal temperature and the metal surface condition on the fire spread rate along mild steel and aluminum cylinders have been studied experimentally for wide variations of the oxygen pressure, up to 10 MPa, and the test piece temperature, up to the melting points. Based on the experimental results, the mechanisms by which fire spread is controlled, and the dependence of the fire spread rate on the metal temperature and the metal surface condition have been discussed.

The experimental results show that the fire spread rate does not always increase with the increase of the metal temperature, but the two cases, the increase or the decrease, exist corresponding to the ranges of the oxygen pressure and the metal temperature. The curious dependency of the spread rate on the metal temperature is attributable to the variation of the heat transfer rate from the molten mass to the unburned solid caused by the change of the contour of the boundary surface between the molten mass and the unburned solid metal. The effect of the surface condition on the fire spread rate is small. In this case, the variation of the fire spread rate is mainly attributable not to the variation of the surface reaction rate or the heat transfer rate at the solid metal just above the molten mass, but to the variation of the heat transfer rate from the molten mass to the unburned solid.
Burn Propagation Rates of Metals and Alloys in Gaseous Oxygen
Authors: Benz FJ , Shaw RC , Homa JM
Published: December 2008

The average burn rates of several metals and alloys were determined at oxygen pressures between 3.45 and 68.91 MPa (500 and 10 000 psig) and ambient temperature. Several materials were tested at elevated sample temperatures. The test materials were fabricated into solid cylindrical rods and mounted vertically in the test chamber. A magnesium igniter was positioned at the bottom end of each test specimen to promote upward burn propagations.

Nickel 200 and copper 102 could not be ignited at all oxygen pressures tested whereas Monel 400 appeared to ignite but quickly self-extinguished. The other materials tested burned the entire length of the test sample. Aluminum 6061 exhibited the fastest burn propagation rate. Inconel 718 burned slower than aluminum but faster than the stainless steels (Types 304 and 316).

Increasing oxygen pressure generally increased the burn propagation rate of the materials. Increasing the ambient temperature of the test specimens for several materials to approximately 850 K (1070°F) had little effect upon the ignition or burn properties of Nickel 200 or Monel 400. Type 316 stainless steel exhibited an increase in its burn propagation rate at this higher temperature.
Case Study of Royal Australian Air Force P3B Orion Aircraft Ground Oxygen Fire Incident
Authors: Grubb JW
Published: December 2008

In Jan. 1984, the Royal Australian Air Force (RAAF) experienced a ground fire incident that destroyed a six million dollar P3B Orion Aircraft (A9-300). The incident occurred during removal of an onboard oxygen cylinder, one of three that supply the Orion flight crew. Examination of the aircraft's oxygen system revealed that the fire had initiated in an oxygen manifold check valve (MCV) assembly. The primary cause of the incident was a leaking poppet valve, which allowed oxygen stored at 12 MPa (1800 psi) to escape to atmosphere. Deterioration of the silicone rubber seal and galvanic corrosion are believed responsible for the valve failure. Contributory causes to the fire were system contamination and failure to bleed the oxygen system before cylinder disconnection. A thermite reaction involving the aluminum MCV assembly, metal particles, and metal oxide particles was the most likely cause of ignition. RAAF investigations revealed similar contamination throughout the entire fleet of P3B/C Orion aircraft; iron oxide dust was the major contaminant found. Oxygen system filters were also examined, and trials aimed at improving particulate matter filtration are currently being conducted. Extensive cleaning of both aircraft oxygen systems and ground support equipment was also undertaken.

RAAF findings, supported more recently by the U.S. Navy investigations, indicate the need to consider using materials other than silicone rubber in oxygen systems. Further research into the ignition of aluminum and other candidate materials through metal particle impingement in the presence of metal oxides in a high-pressure oxygen environment is also required.
Use of Material Characterization to Complement Fracture Mechanics in the Analysis of Two Pressure Vessels for Further Service in a Hydrogenating High-Temperature Process
Authors: Rahka K
Published: December 2008

Cracks of significant size were found in two chemical process pressure vessels after around 100 000-h service. The finding warranted fracture mechanics evaluation of further service fitness. This was done in five steps: fracture toughness measurements including determination of aging effects, loading limit identification including estimation of further aging and hydrogen effects, stress-intensity factor calculations, material and cracking mechanism investigation, and recommendations of precautions. The principal reason for crack formation was found to have been hydrogen attack due to local insufficient alloying in repair welds. Sufficient safety margins for further service were provided by a combination of precautions during startup and shutdown operations, low-working stresses, and sufficient fracture toughness as well as a detailed service record. Recommendations for further precautions included more frequent and intensified recurrent inspection, inert gas pressurization, and limitation of process pressures at ambient and lower temperatures during startups and shutdowns.
Cracking at Nozzle Corners in the Nuclear Pressure Vessel Industry
Authors: Smith CW
Published: December 2008

Cracks in nozzle corners at the pressure boundary of nuclear reactors have been frequently observed in service. These cracks tend to form with radial orientations with respect to the nozzle central axis and are believed to be initiated by thermal shock. However, their growth is believed to be primarily due to a steady plus a fluctuating internal pressure. Due to the impracticality of fracture testing of full-scale models, the Oak Ridge National Laboratory instituted the use of an intermediate test vessel (ITV) for use in fracture testing which had the same wall thickness and nozzle size as the prototype but significantly reduced overall length and diameter. In order to determine whether or not these ITVs could provide realistic data for full-scale reactor vessels, laboratory models of full-scale boiling water reactors and ITVs were constructed and tested. After briefly reviewing the laboratory testing and correlating results with service experience, results obtained will be used to draw some general conclusions regarding the stable growth of nonplanar cracks with curved crack fronts which are the most common precursors to fracture of pressure vessel components near junctures. Use of linear elastic fracture mechanics is made in determining stress-intensity distributions along the crack fronts.
Fracture Analysis of Propane Tank Explosion
Authors: Pearson HS , (Jesse) Dooman RG
Published: December 2008

A truck-mounted propane tank exploded. The failure occurred through a girth weld, causing a section of the dome to fly from the tank. Initial evaluation of the failed tank showed a crack existed in the girth weld, for several years. The preliminary conclusion of this investigation was that the crack condition was the cause of failure; however, the authors suggested that a fracture mechanics analysis be conducted.

Four compact fracture toughness specimens were fabricated from weld metal in the tank and tested. It was shown that the failure could not have occurred from the existing crack and the tank internal pressure, unless the internal pressure far exceeded the maximum allowable 1.72 MPa (250 psi) pressure.

Further investigation led to the discovery that the relief valve of the tank was corroded so badly that it would not open, thus allowing excessive pressure in the tank. There was evidence that the driver had overfilled the tank. Heat from the sun and from the hot truck tailpipe caused the tank to become liquid full. Then, the pressure exceeded 6.9 MPa (1000 psi), causing the tank to explode. The fracture mechanics analysis thus showed that the explosion was not due only to the existing crack, but also to the stopped-up relief valve and excessive liquid propane in the tank.
Choosing a Steel for Hydroelectric Penstocks
Authors: Reid CN , Baikie BL
Published: December 2008

This case history concerns the design of the high pressure water pipes (penstocks) of the Dinorwig pumped storage power station. The first part describes an Open University teaching exercise which is based on the original assessment performed by Milne of the Central Electricity Generating Board. It involves the consideration of two contending steels, “A” and “B,” and the selection and justification of a preferred choice. Since the hydraulic loading contains cycles of changing pressure, the fatigue lives of the penstock designs were compared. The possible presence of longitudinal surface cracks was considered, with a depth equal to the limit of ultrasonic detection (taken to be 6 mm). The Paris-Erdogan equation was used to calculate the length of time required to grow a fatigue crack from this depth up to the critical size. Comparing designs of equal cost, that in Steel B achieved a much longer “crack growth lifetime” and was the preferred choice. Finally, defect acceptance standards were drawn up for this design.
Observations, Predictions, and Prevention of Fatigue Cracking in Offshore Structures
Authors: Reemsnyder HS
Published: December 2008

In the past, during transit of jack-up offshore drill rigs, vortex shedding caused the initiation of fatigue cracks at certain details. The problem was defined as an interaction of cyclic stresses introduced by column vortex shedding and tensile residual stresses in the details. The paper outlines two simultaneous approaches to solution of the problem: (1) elimination of vortex shedding through structural modifications, that is, addition of helical strakes or spoilers, and (2) determination, by experiment, whether thermal stress-relief was beneficial. Also reviewed are the development and experimental corroboration of a local-strain life prediction method applicable to this and other structural fatigue problems.
Failure Analysis of a Large Wind Tunnel Compressor Blade
Authors: Hampton RW , Nelson HG
Published: December 2008

A failure analysis was performed to establish the cause and prevent the recurrence of a 2014-T6 aluminum compressor blade failure in a large NASA-Ames Research Center wind tunnel. A metallurgical failure analysis showed that a 0.13 mm (0.005 in.) deep scratch in the shank of the blade had acted as an initiation site for a fatigue crack. The crack subsequently grew by Stage II fatigue across most of the blade's 22.9-cm (9-in.) base transition region before final fracture occurred by unstable crack growth. Extensive fractographic characterization of both the blade and laboratory specimens was performed using a scanning electron microscope. Surface morphology, including fatigue striations, was used to estimate the vibration stress levels, the time to grow the crack, and the magnitude of the local mean stress present.

A structural failure investigation was conducted to determine the resonance vibration condition which made the blade sensitive to a scratch. Studies of the blade natural frequencies were made to determine the mode responsible for the vibrations which grew the crack. The effect of the crack on modal frequency was measured and computed. Tunnel measurements were used to determine the vibration resonance tunnel speed, magnitude, and source. These data were used to compare with the crack growth data from the fractographic studies and to make recommendations to avoid future blade failures.
Fatigue Crack Growth Predictions of Welded Aircraft Structures Containing Flaws in the Residual Stress Field
Authors: Chang JB
Published: December 2008

Welded structures often contain flaws or crack-like defects. The need to develop a reliable methodology to predict the fatigue crack growth behavior of such flaws, whether embedded in the body or exposed to the surface of the welded structure, is obvious. This paper describes the use of the analytical prediction methodology implemented in a computer code, EFFGRO III, for performing the fatigue crack life prediction of an embedded flaw contained in a welded aircraft structure subjected to a fully reversed flight spectrum loading. Effects of residual stresses to the crack growth were accounted for in the analytical prediction. Results of the analytical prediction were compared to the test data. Good correlations were shown.
Fatigue and Fracture Mechanics Analysis of Compression Loaded Aircraft Structure
Authors: Rich DL , Pinckert RE , Christian TF
Published: December 2008

During depot maintenance of a U.S. Air Force F-15 fighter aircraft, cracks were discovered in the wing upper spar cap at the inboard end of the spar. Since the upper spar cap is a compression member during normal flight, these cracks were an unanticipated phenomenon which required extensive fatigue and fracture mechanics analyses. The tensile stresses resulting from maneuvers and landing were not considered sufficient to cause cracking. Investigation indicated that the local stresses around holes in the compression-loaded spar cap exceeded compression yield, and, upon unloading, residual tensile stresses were induced at the holes. To determine this cause and the exact nature of service loadings, analytical and experimental studies were performed. A large, detailed finite element model was constructed to determine the local loads in the area of fastener holes. A comprehensive program of element specimens subjected to spectrum loading was also conducted to simulate the in-service cracking and determine the effectiveness of various repair configurations. Crack initiation and crack growth characteristics were obtained from the tests.

The number of flight hours to crack initiation at the side of the critical fastener hole was predicted. Crack growth analyses were made using a contact stress model computer program, modified to take into account the residual stresses adjacent to the fastener hole. The results of this crack growth analysis are being used to guide Air Force planning for in-service modifications of aircraft.
Fracture of an Aircraft Horizontal Stabilizer
Authors: Howard IC
Published: December 2008

The paper shows how fracture mechanics can be used on data given in the accident report of the crash of a Boeing 707 at Lusaka to predict the fracture toughness of the material from which the cracked component was made, and to estimate the load transferred within the stabilizer by the arrest of this crack.
Fatigue Life Analysis of Fuel Tank Skins Under Combined Loads
Authors: Saff CR , Ferman MA
Published: December 2008

The superposition of high- and low-frequency loadings has caused numerous fatigue crack problems throughout the history of metal airframes. Fighter aircraft fuel tanks are subjected to the superposition of low-frequency (0.1 to 1 Hz) maneuver loads and high frequency (50 to 300 Hz) vibrations due to panel flutter and fuel slosh. This loading can lead to cracks, and leaks, in shorter times than can be predicted by using either load condition alone. This paper examines two methods for predicting fatigue lives under combined high- and low-frequency loadings. Tests of beam element specimens and a simulated fuel tank were used to examine prediction accuracy of both techniques. Results show that both techniques accurately predict the effects of combined load frequencies on life when adjusted to correlate predictions with the extreme (high- and low-) frequency data.
Aircraft Structural Maintenance Recommendations Based on Fracture Mechanics Analysis
Authors: Denyer AG
Published: December 2008

The paper discusses the implementation of the Force Management (FM) phase of the Aircraft Structural Integrity Program (ASIP) for a USAF utility transport/trainer aircraft. The analyses, performed in support of the Force Management tasks, use the principles of linear elastic fracture mechanics with emphasis on subcritical flaw growth. The durability and damage tolerance lives, generated with a crack growth computer program, are the basis for structural maintenance recommendations and inspection intervals presented to the USAF in the Force Structural Maintenance Plan (FSMP).

The case study considered herein shows how the T-39 wing, designed to the fatigue requirements of the late 1950s, performs to the structural criteria of the 1980s as defined by the military specifications MIL-STD-1530 and MIL-A-83444.

The initial FM task was the durability and damage tolerance assessment (DADTA) of the structure based on the current service usage as defined by the loads/environment spectrum survey (L/ESS). An outline of the necessary spectrum development is provided, as is the crack growth analyses leading to estimates of the economic life and structural life enhancement recommendations.

The DADTA was followed by the institution of the individual aircraft tracking (IAT) program, the purpose of which is to compute the rate at which the available structural life of each aircraft is being used and to establish inspection intervals to ensure safety. Tracking is accomplished by compiling flight records, collected by means of pilot logs containing mission information for each flight. The paper will show the economic crack growth procedure used, both to ascertain the accumulated damage based on the flight records and to estimate the remaining structural life.

The conclusion of the paper will discuss the maintenance recommendations and the advantages of using fracture mechanics based aircraft tracking in support of force management.
Role of Fracture Mechanics in Assessing the Effect on Fatigue Life of Design Changes in Welded Fabrications
Authors: Tubby PJ , Wylde JG
Published: December 2008

Experience has shown that in many instances designers have reacted to service fatigue failures in welded structures in the wrong way, with the result that design changes made have not had the desired effect. It is the intention of the present paper to demonstrate that fracture mechanics techniques, which are now well established, can be used to provide an appreciation of those aspects of a design which are important with respect to the fatigue performance of the structure. This understanding provides an excellent basis for evaluating the benefit of proposed design changes when service problems are encountered.

Analysis is based on stress-intensity solutions derived by two-dimensional linear elastic finite element modelling. Fatigue lives are predicted by integration of the appropriate fatigue crack growth law on the basis that the life of a welded joint is dominated by the propagation of small pre-existing defects.

An important consequence of this feature of their behavior is that the fatigue lives, and hence fatigue strengths, of joints are strongly influenced by factors which affect the rate of crack propagation. Results are given which illustrate that factors such as weld profile, the tensile strength of the parent material, and stress relief by post weld heat treatment have little effect on fatigue strength, although historically designers have often looked to modify one of these in the face of service problems. Other factors such as the detailed design of joints and the reduction of stress concentration factors are shown to be more significant.

It is also demonstrated that even the most fundamental step in the design process, that is, the selection of scantlings, may not have the expected effect on fatigue life since the fatigue strength of a joint may be reduced by increasing the plate thickness.
Failure Analysis of a Total Hip Femoral Component: A Fracture Mechanics Approach
Authors: Rimnac CM , Wright TM , Bartel DL , Burstein AH
Published: December 2008

Failure analysis was conducted on 21 fractured femoral components from Trapezoidal-28™ total hip replacements performed at The Hospital for Special Surgery. These components were made from 316L stainless steel and had a trapezoidally shaped cross section in the neck and stem portions. Fractographic examination revealed multiple cracks on the medial side of the stems and a fracture surface with crack initiation sites from both the medial and lateral surfaces. Electron microscopy revealed striations on the fracture surfaces of both medial and lateral cracks, indicating that crack growth occurred by a fatigue fracture process in both cases. Analytical examination using curved beam theory with a bilinear stress-strain relationship predicted the medial cracks to initiate first, due to residual tensile stresses following an overload. In the presence of a medial crack, higher tensile stresses were predicted on the lateral side, making it the next most likely site for crack initiation. Fracture occurred when a lateral crack joined with a pre-existing medial crack. It was concluded this fracture mode was due to the combined effects of the trapezoidal stem design and the mechanical properties of 316L stainless steel.
The Hazard Communication Program at 3M: “You Need to Know”
Authors: Butenhoff JL , McCormick WC
Published: December 2008

The organizational structure and diversity of 3M has led to the development of a unique system of hazard communication to meet both internal and external needs. 3M is a diversified manufacturer operating in 53 countries with some 6600 kinds of products with annual sales over $8 billion. The large number of raw materials and intermediates used to make these products dictate that 3M has a large responsibility in regard to the Occupational Safety and Health Administration (OSHA) Hazard Communication standard.

A corporate hazard communication committee representing various staff groups has developed a compliance plan. The Medical Department is taking the lead in this effort. The hazard communication programs can be divided into internal programs and external programs. These encompass and provide direction for the major elements of hazard communication. 3M has adopted the phrase “you need to know” as a catchword of the hazard communication program. This paper describes the various aspects of the 3M compliance program.
Right-To-Know Legislation in New York State: Provisions and Implementation
Authors: Stone RR
Published: December 2008

Many states and localities have passed “right-to-know” legislation in the absence of federal activity in this area. In doing so, they face the dilemma of establishing mandatory informational programs to improve job safety, yet not burdening employers to the extent of losing jobs within their jurisdictions. The Right-To-Know Law in New York State has successfully implemented a program which guarantees employees information on all chemicals for which data exist [as listed in the Registry of Toxic Effects of Chemical Substances (RTECS)], yet has a minimal employer impact. The law is comprehensive in terms of the number of employees and the number of chemicals covered. The smooth implementation of this law is due to reliance on easily available information sources [Material Safety Data Sheets (MSDSs)] and the establishment of a technical resource within the state to assist employers with the gathering of information. This has been particularly important for the smaller businesses that do not retain staff physicians or industrial hygienists. This paper describes the essential features of New York's law and the outreach program that was developed for its implementation.
Overview of the Implementation of a Statewide Worker and Community Right-to-Know Act
Authors: Garie HL , Chess C , Stevenson E
Published: December 2008

New Jersey's Worker and Community Right-to-Know Act requires employers to report information about toxic substances used, stored, or released from facilities in the state. This information is made available to the public and is directly transmitted to the Department of Environmental Protection (DEP), local emergency response personnel, and county health departments. The collection of this information enables the DEP to develop a comprehensive database of toxic substance use in the state.

The DEP has developed two surveys to gather information from employers covered by the act. The Emergency Services Information Survey, which gathers information about materials that pose potential safety hazards, requires the reporting of materials on the United States Department of Transportation's Hazardous Materials Table. The Environmental Survey, Part I requires employers to report information about a DEP-compiled list of 154 substances that have the potential to cause chronic health effects or to cause damage to the environment. After a scientific review of data provided on the Environmental Survey, Part I, the DEP will require selected employers to report additional, detailed information about emissions and discharges of hazardous substances.

The centralized database that is developed from information reported in these surveys will enable the DEP to improve public health protection and to guide new efforts in environmental monitoring and regulation.
Methodology for Selecting Impact Tests of Composite Materials in Automotive Applications
Authors: Roche JL , Kakarala SN
Published: December 2008

The concept of a “good impact test” has two aspects: the quality of the test results and the applicability of the test results. The quality of output from various impact tests is the subject of a companion paper. This paper presents a methodology for selection and interpretation of impact tests for automotive composites. Proper selection and interpretation can provide good correlation between test results and performance in application.

A necessary condition for obtaining correlation between test results and service performance is that the key impact parameters in an end-use impact event are identified and duplicated in the test method. The key impact parameters—stress state, controlling variable, and failure limit—are defined and developed from the special characteristics of composite materials.

The starting point of the methodology is a set of simple statements of the impact-related functional requirements of the application. A procedure is presented for systematically transforming these statements into a characterization of the application in terms of key impact parameters. Test methods that match this characterization are specified.

As an example, the methodology is applied to an automobile fender. A set of test methods is specified. Characterizations of six additional automotive applications are summarized, and implications for future test method development are discussed.
Instrumented Dart Impact Evaluation of Some Automotive Plastics and Composites
Authors: Knakal CW , Ireland DR
Published: December 2008

This paper presents a guide for evaluation and utilization of data provided by the instrumented dart impact test. This guide was developed after evaluating seven different plastics and composites, different probe diameters, impact velocities, and different test temperatures. These were instrumented tests that yielded complete load and absorbed energy profiles as a function of probe penetration distance. A special high-speed video technique was used to develop an understanding of and confidence in interpretation of the major features of the load-deflection profile.

The concepts and comments are applicable to other techniques of dart impact testing. An important element of this paper is its application to widely differing data records and the recognition that the data analysis should not be forced for certain types of data records.
Experimental Comparison of Several Impact Test Methods
Authors: Kakarala SN , Roche JL
Published: December 2008

The results of a statistical evaluation of ten impact test methods are presented in this paper. The concept of “good impact test” has two aspects: the quality and the applicability of the test results. The applicability of various test methods for predicting in-service performance is the subject of a companion paper. This paper presents an evaluation of the quality of the test output, as well as an analysis of the correlation between various test outputs.

The ten test methods evaluated—three pendulum, one tensile, four drop dart, one flex, and one driven dart—are described briefly. Three of the test instruments were instrumented. Seven materials, ranging from unfilled thermoplastics to reinforced thermosets, were tested by each of the methods.

Evaluation of a test's output quality is developed in terms of the range of applicability and the degree of material differentiation. Specific factors that serve as criteria include the existence and distinctness of failure, and the spread and scatter of measured results. The test methods are ranked from “highly desirable” to “severely restricted.”

Evaluation of the correlation of material ranking by the various test methods is presented. In general, results from different impact tests do not correlate. However, there are instances of strong or fair correlation. The degree of correlation is explained in relation to the similarity of test stress states and measured characteristics. It is meaningful to classify impact tests according to stress states and measured characteristics. Material selection for impact performance should be based on test methods that simulate the stress states, controlling variables, and failure limits of the intended application.
Impact Response of Polymeric Materials at Varying Depths of Penetration
Authors: Lee WM , Predebon WW , Jurosek ML
Published: December 2008

Usually, an impact test is conducted to the point of fracture, so that the fracture energy and other fracture properties of a material under impact loading conditions can be assessed. To understand the fundamentals of and gain insight into impact phenomena, it would be valuable to monitor and quantify the deformation mechanics in a material leading to fracture and to relate the deformation profile history to the resulting impact traces. This task is accomplished in the present paper by carrying out impact tests at varying depths of penetration using a Rheometrics impact tester. The materials under investigation are a rubber-modified polystyrene [high-impact polystyrene (HIPS)] and a high-density polyethylene (HDPE).

The force-displacement traces of partial impacts of these two materials are presented and compared with those at fracture. The effects of impact speed and clamp ring size are also discussed. The two polymers, being ductile in nature, exhibit indentation deformation before complete puncture occurs. The deformation profile/impact force/ram displacement relationship is established.

The present study also includes a computational analysis of the impact response in polymeric materials. The impact model makes use of a finite-difference wave mechanics code. A wave mechanics approach is used in order to include the effects of inertia in the development of deformation and stress states under impact conditions. It incorporates a critical stress criterion for incipient damage and a damage assessment on the basis of stress-time accumulation. Comparisons are made between the calculations made at high impact speeds and those from the impact experiments conducted at low speeds. The computer simulation and experimental results are in qualitative agreement.
Air Leakage and Fan Pressurization Measurements in Selected Naval Housing
Authors: Lagus PL , King JC
Published: December 2008

Data from detailed tracer concentration decay and induced pressurization measurements were obtained in tests of duplex and row apartments at Norfolk, Virginia and Pensacola, Florida to accurately determine air leakage characteristics of selected naval housing. Local meteorological information also was collected to facilitate comparison of predicted versus measured air leakage rates. For the Norfolk data, the 4-Pa leakage areas inferred from pressurization/depressurization measurements are uniformly lower than those calculated from the measured tracer dilution air leakage rate via the Sherman air leakage model.

Considerable tracer dilution testing was performed on a single unit of duplex housing at Pensacola. Air leakage testing within rooms of this unit disclosed a uniformly low air leakage rate. The data also illustrated the directional nature of air leakage in a duplex. Of particular additional interest were two measurements taken over a 24-h period utilizing a single tracer injection followed by monitoring of dilution decay. Samples were taken by the container method and analyzed.
Parameters Affecting Air Infiltration and Airtightness in Thirty-One East Tennessee Homes
Authors: Gammage RB , Hawthorne AR , White DA
Published: December 2008

A major pathway for loss of conditioned air in east Tennessee homes with externally located heating, ventilation, and air-conditioning (HVAC) systems is leakage in the ductwork. The effect on infiltration rates, as measured by Freon-12 tracer gas dilution, becomes marked if the central duct fan is operating; duct-fan on and duct-fan off measurements of the rate of air exchange gave mean values of 0.78 and 0.44 h−1, respectively, in a total of 31 homes. Specific leakage areas measured by the blower-door, pressurization-depressurization technique are affected to a lesser extent by inclusion of the ductwork volume within the total volume of the house that is being pressurized. A subset of seven of the study homes were measured using this technique; the average increment in the specific leakage area was about 15%. Leaking ductwork in attached garages also causes degradation of the indoor air quality by pulling in pollutants such as gasoline fumes from automobiles and distributing them throughout the house. In dealing with homes that have central HVAC systems, weatherization and energy conservation programs should be cognizant of the seriousness of air and energy losses caused by leaking ductwork as well as possible degradation of the indoor air quality.
Average Infiltration Rates in Residences: Comparison of Electric and Combustion Heating Systems
Authors: Goldschmidt VW
Published: December 2008

Research and test results presenting measurements of air infiltration rates in residences are reviewed. In particular, comparison of electric and combustion heating shows (on the average) infiltration rates to be 0.1 to 0.25 higher for residences with combustion heating.
Air Infiltration Measurements in Large Military Aircraft Hangars
Authors: Ashley JL , Lagus PL
Published: December 2008

Air leakage measurements by the tracer dilution technique were performed in five military aircraft hangars. The hangars were located in regions of the country having diverse weather characteristics. In several of the hangars, distinct measurements were performed to assess the degree of homogeneity of the air-tracer gas mixture in these large volume structures. Air leakage rates in the range of 0.6 to slightly above 2.0 air changes per hour (ACH) were measured. Surprisingly, these values do not differ significantly from those which might be measured in single-family residences. Since, in use, aircraft hangars often have at least one sliding door open, tracer dilution measurements were performed to show the increase in air leakage to be expected with one and two (oppositely located) doors open.
Demonstration of Air Leakage Reduction Program in Navy Family Housing
Authors: Verschoor JD , Collins JO
Published: December 2008

The Department of Defense has an ongoing program to conserve energy at its installations. One method of energy conservation in residential units is the reduction of excessive air leakage by appropriate retrofits.

Under the sponsorship of the Office of Navy Family Housing, a demonstration of air leakage reduction was undertaken at the Great Lakes Naval Training Center. Two procedural documents were prepared in draft form: a manual for use by supervision and a handbook for the on-base mechanics doing the air leakage retrofits. The retrofits were designed to be incorporated at the time of change of occupancy, when routine interior maintenance and refurbishing are normally scheduled.

The demonstration consisted of measuring the “before” air leakage rate of each unit by the fan depressurization method. Major air leakage sites were noted. Retrofits were made in about half of the units, and the resulting reduction in air leakage was measured. Air leakage data are presented on a representative sample of 65 units of the housing inventory at Great Lakes.
Field Performance of an Air Infiltration Barrier
Authors: Weimar RD , Luebs DF
Published: December 2008

A spun-bonded polyolefin air infiltration barrier (AIB) was installed immediately beneath the siding of a 5-year-old, ranch-style house [conventional comparison house (CCH)]. The AIB reduced the heating energy consumption by 24% during the first heating season and is expected to reduce the heating load by 28% over the remaining life of the house.

This test confirmed earlier field studies and allowed the development of the mechanism by which AIBs function and the recommendation of required AIB physical properties.
An Evaluation of the Effectiveness of Air Leakage Sealing
Authors: Giesbrecht PG , Proskiw G
Published: December 2008

A field study was carried out to evaluate the effectiveness of air leakage sealing techniques for reducing air infiltration in houses. Presealing and postsealing air leakage tests were performed upon 82 single detached houses. All of the houses were located in Winnipeg or southern Manitoba, a region with an annual degree day value (Celsius) of about 5800. The sample group consisted of 56 conventionally constructed houses of varying size, style, occupancy, and airtightness and 26 nonstandard structures of smaller but identical size and age. This latter group was part of the Flora Place project.

All houses were placed under a negative pressure, and leakage sites were identified using smoke pencils. Windows and doors were weather-stripped and other unintentional openings caulked and sealed using specified materials and techniques.

Based upon the results of the study, the median reduction in airtightness of the conventional structures, defined using the equivalent leakage area at 10 Pa (ELA10), was 31.6% with significant variations occurring both between houses of the same type and between different types of construction. When the houses are examined in groups according to type of construction, it is apparent that the greatest reduction in ELA (36.9%) was achieved in single-story houses. Houses constructed in somewhat more complicated fashion, such as split levels, exhibited less of a reduction. As a group, two-story houses showed the least reduction (24.4%), likely due to the indirect leakage between floors that could not be addressed properly. Within any group, houses with inaccessible air leakage points, such as in finished basement areas, showed the least reduction. The median reduction in the ELA10 for the Flora Place houses was 42.5%, again with significant variations between houses despite their near-identical construction.

Using the air leakage test data and a recently developed correlation model, an estimate was made of the naturally occurring air infiltration rates for all the test houses. This analysis indicated that the sealing produced a median reduction in the infiltration rate of 32.8% for the conventional houses and 46.1% for the Flora Place houses. Due to a lack of equipment, tracer gas tests were not conducted to confirm these values.

Note, however, that the results of this study likely are representative of houses constructed only in Manitoba and possibly in Saskatchewan and Alberta. Since houses in the prairie provinces tend to have low air infiltration rates, the effects of air leakage sealing on houses in other parts of the country could be different from those found in this study.