bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Low-Velocity Impact Damage on the Fatigue Behavior of Graphite/Epoxy Laminates
Authors: Ramkumar RL
Published: March 2009

This paper discusses an experimental program that addressed the effect of low-velocity impact damage on the fatigue behavior of two laminates, fabricated from AS/3501-6 graphite/epoxy unidirectional tapes, with lay-ups representative of high-performance fighter aircraft wing skin lay-ups. Prior to testing, specimens from these laminates were subjected to one of two types of low-velocity impact damage. The first type was created using a blunt-tipped (1.6-cm tip diameter) impactor, and the impact energy was chosen to induce internal damage, approximately 5 cm in diameter, with no visible sign of damage on the outer surfaces. The second type of damage was created using a sharp (tetrahedral-tipped) impactor, with visible signs of damage on the impacted and opposite surfaces. Subsequent to introducing low-velocity impact damage, test specimens were subjected to static and constant amplitude fatigue loading. In the presence of compressive loads, lateral knife-edge supports were placed near the outer edge, for specimen stability, permitting unconstrained delamination growth elsewhere. Static tension and compression tests were conducted initially, and significant strength reductions due to the impact damages were measured. Fatigue load amplitudes were chosen to be fractions, S, of the static strengths. The behavior of impact-damaged specimens was investigated under tension-tension (R ≈ 0), tension-compression (R = −1), and compression-compression (R → −∞) fatigue loads. During fatigue, the growth in the impact damage was monitored by means of ultrasonic pulse-echo records. Fatigue life data for the various laminate-damage-loading combinations were obtained in the form of S-N curves. Interesting damage growth patterns were observed, and the criticality of each type of impact damage on the fatigue behavior of the tested laminates was assessed.
NRC Safety Research Priorities for Reactor Vessel Embrittlement, Annealing, and Surveillance Dosimetry
Authors: Serpan CZ
Published: March 2009

The recent definition of a postulated thermal shock accident followed promptly by system repressurization, termed an overcooling or pressurized thermal shock accident, has set a large analysis and research effort into motion. The essential elements are concerned with defining the accident transients, evaluating the instrumentation and controls that cause the postulated accidents, and evaluating the metallurgical and structural mechanics aspects of the reactor vessel with respect to its failure potential. This paper poses the question faced by the Nuclear Regulatory Commission (NRC) for the vessel steel embrittlement, annealing, and surveillance dosimetry facets of this postulated accident and provides information on our plans for study of this problem as well as current status.
Determination of Neutron Damage Parameters for Irradiation Embrittlement
Authors: Lippincott EP , McElroy WN
Published: March 2009

Programs for improvement in evaluation of damage exposure parameters for irradiation embrittlement in pressure vessel steels are currently under way. Results will be implemented through a series of ASTM standards which will enable radiation damage to be consistently predicted with increased confidence and with well-defined uncertainty trends.
Role of the Active Defect Complex in the Neutron Embrittlement and Thermal Recovery of High-Copper Reactor Pressure Vessel Steels
Authors: Highton JP
Published: March 2009

Annealing studies of irradiated and unirradiated pressure vessel steel have led to the conclusion that an active defect complex (ADC) is responsible for the enhanced embrittlement associated with steels containing significant levels of copper (>0.1%). These complexes, which already exist in the unirradiated steel, accumulate vacancies, produced either thermally or by neutron bombardment, and grow to such a size that the dislocation mobility is impaired and the yield stress increased. The number density of the sites appears to be a function of the copper level in the steel. Thus in low-copper steels the site spacing is too great to affect the yield stress.

The stable size of the complex seems to be an inverse function of temperature. Thus after preservice stress relief heat treatment the sites are too small to influence the mechanical properties of the vessel steel. At lower temperatures, however, exposure to a vacancy flux causes the sites to grow to their equilibrium size at a rate determined by both the availability of vacancies and the number density of the sites. Postirradiation annealing will cause the ADCs to shrink to a size that is stable at the annealing temperature. The ADCs also act as traps to positions and cause the line shape of the 511-keV annihilation peak to narrow. This effect appears to be related to the site size. Herein lies a prospect for remote interrogation of a reactor pressure vessel to assess the state of embrittlement resulting from this mechanism, both through life and after annealing.
A Fracture Energy Criterion for Irradiation Research and Surveillance
Authors: Gillemot F , Kapitány A
Published: March 2009

Measurement of the fracture toughness properties of irradiated materials presents many difficulties because of the limited volume of the specimens. One solution to this problem lies in the use of the fracture energy criterion, which is valid for high plastic deformation. The Absorbed Specific Energy Until Fracture (ASPEF) criterion was used for evaluating irradiation research results and a correlation was found between this criterion and the fatigue crack propagation rate on nonirradiated steels, thereby providing a basis for using ASPEF to evaluate surveillance results.
Phase-Resolved Nanosecond Spectrofluorometry: Theory, Instrumentation, and New Applications of Multicomponent Analysis by Subnanosecond Fluorescence Lifetimes
Authors: Mattheis JR , Mitchell GW , Spencer RD
Published: March 2009

We describe a new method, phase-resolved subnanosecond spectroscopy (PRS), for the spectral differentiation of fluorophores in a mixture. The technique required adding a phase-variable rectifying detector to the SLM 4800S phase-spectrofluorometer. The theory of PRS is based on the sinusoidal fluorescence emission of a population of molecules in response to sinusoidally modulated excitation light. The total a–c fluorescence signal is passed through the phase-variable detector which nulls the emission signal of any component in quadrature with the reference angle. The emission characteristics of the remaining component, or components, are more readily and accurately revealed. We investigated the sensitivity and selectivity of PRS. The sensitivity of PRS was demonstrated by nulling the contribution of the Raman scatter band of a nanomolar solution of quinine bisulfate to the real-time emission spectrum resolved at 8-nm bandpass. We demonstrated the selectivity of PRS by resolving the emission spectrum of anthracene and perylene from a 1 : 1 mixture with a lifetime differential of only 600 ps. Also, the emission spectra of 2,2-phenylene bis-(5-phenyloxazole) and dimethyl 2,2-phenylene bis-(5-phenyloxazole) were also resolved from a 1:1 mixture in ethanol. The lifetime differential here was only 200 ps.

We also applied the PRS technique to investigate the heterogeneous emission due to tyrosine and tryptophan residues in the protein bovine serum albumin (BSA). Suppression of the fluorescence emission of tryosine at 300 nm allowed us to resolve the emission spectrum of tryptophan. Suppression of the fluorescence emission of tryptophan at 400 nm allowed us to resolve the emission spectrum of tryosine. The PRS spectra of the two components suggested the presence of an additional species that may add to the heterogeneous emission of the protein.
Analysis of Heterogeneous Emissions by Multifrequency Phase and Modulation Fluorometry
Authors: Jameson DM , Gratton E
Published: March 2009

The technique of multifrequency phase and modulation fluorometry may be applied to the measurement and analysis of heterogeneous fluorescence lifetimes. This paper addresses two approaches to the data analysis: (1) the exact analytical solution (Weber's algorithm) for determining the lifetimes of N components and their relative contributions using N modulation frequencies and (2) a least-squares method. The mathematical rationale for each approach is described and the effects of random or systematic errors on the results obtained with each method are discussed. The relative merits of each approach are considered in light of results on both real and simulated data.
Correcting Emission and Excitation Spectra: A Review of Past Procedures and New Possibilities Using Silicon Photodiodes
Authors: Zalewski EF , Geist J , Velapoldi RA
Published: March 2009

A brief review of procedures used to produce corrected excitation and emission spectra is given. Recent advances in silicon photodiodes as detector standards and the possibility of their use to produce both corrected excitation and emission spectra are discussed in more detail. The advantages in the use of the photodiodes based on accuracy, stability, simplicity of use, and extensive linear dynamic range will be reviewed.
Atmospheric Sulfur Analysis Using Rateometric Colorimetry
Authors: Kimbell CL , Kimbell CL
Published: March 2009

This paper describes a method of measurement of sulfur compounds in liquid and gases from 0 to 100 parts per billion by volume. It is applicable to atmospheric sulfur measurements. Equipment using this method is suitable for mobile mounting in an automobile, helicopter, or airplane.
Laboratory Measurement of Pesticide Vapor Losses
Authors: Holoman S , Seymour KG
Published: March 2009

A laboratory technique for measuring the vaporization rate of a formulated pesticide from spray deposits has been developed. Surface preparation and deposit coverage on a glass substrate will exert some effect on the precision of the measurement. This method is useful in comparing the relative volatilities of a pesticide from various formulation batches and for studying the effects that additives to a formulation have on the vaporization rate of the pesticide.
Helicopter Application for Gypsy Moth in Residential Communities
Authors: Voss CM
Published: March 2009

The gypsy moth threat to urban residential properties and the use of aerial application of pesticides for control is creating a set of specific operational problems for the spray pilot. Instead of dealing with one farmer customer per job he now faces large numbers of urban customers in the thousands per job. Their environmental concerns need to be answered. Operations need to be tailored on a smaller block scale in order to treat accurately groups of houses with areas to be missed. Prior meetings and organization, along with follow-up critiques, are a necessary part of the program.
Flow Rates of Guthion and Cottonseed Oil Mixtures
Authors: Barnett HG
Published: March 2009

The use of cottonseed or soybean oil as a diluent is becoming increasingly important in ultralow-volume (ULV) application of pesticides. Guthion 2L is registered for ULV application, so it was of interest to study the variables that could affect the flow rates of Guthion 2L oil mixtures through various nozzle tips.

The tests were conducted with a carbon dioxide hand sprayer, with the viscosity, temperature, and pressure as variables.

The mixtures used were 0.235 to 0.47 L (½ to 1 pt) of Guthion 2L in 0.47 to 0.705 L (1 to 1 ½ pt) of cottonseed oil. In each evaluation, the total volume was ∼0.94 L (2 pt). The temperature ranged from 23.9 to 48.9°C (75 to 120°F) and the pressures from 206.8 to 275.8 kPa (30 to 40 psi). Nozzle tips Nos. 8002, 8003, and 8004 were used.

In summary, whenever the ratio of Guthion 2L to cottonseed oil was 1:1, the temperature and viscosity had little effect on the flow rate. If the ratio was changed to 0.235 L (½ pt) of Guthion 2L to 0.705 L (1 ½ pt) of cottonseed oil, there was a significant change in the flow rate through the nozzle tip in relation to the temperature. It appears from the data that a flowmeter may be a necessity to avoid application problems.
Pesticide Delivery to Aquatic Pests
Authors: Sutherland DJ , Carey WF
Published: March 2009

Although pesticide delivery to aquatic pests is a broad subject, attention to two common principles is necessary for efficient control of such pests. These principles are (1) knowledge of the pest's biology and habitat and (2) the delivery of the control agent to that habitat and the availability of the agent to the pest species. The larval mosquito is a suitable example for consideration of these principles. Within its larval habitat, a mosquito species responds to various stimuli that can influence its activity and feeding. Depending on the species, the larval habitat itself further influences larval behavior and also the toxic effect of control agents. The delivery of the control agent in granular form is influenced greatly by the particle size, and, generally, the release of organic insecticides from granules and other solid formulations is not very efficient. The development and ultimate value of entomopathogens, such as Bacillus thuringiensis, Serotype H-14, will depend greatly on formulation technology, since toxicity depends on ingestion and the extent to which this agent remains within the larval feeding zone. Since mosquito species, their habits, and their habitats are so variable, single all-purpose formulations of organic insecticides or entomopathogens are only generally effective. To increase effectiveness, technology should develop several formulations, each designed for specific pest species and habitats.
Cumulative Damage: Reliability and Maintainability
Authors: Kozin F , Bogdanoff JL
Published: March 2009

A new cumulative damage model is described. It is shown how the major sources of variability present in cumulative damage combine in a natural manner to form the general structure of the model and how this structure plays a fundamental role in the assessment of the reliability and maintainability of a component of a structure.
Effect of Compressive Loading on Fatigue Crack Growth Rate and Striation Spacing in Type 2219-T851 Aluminum Alloy
Authors: Albertin L , Hudak SJ
Published: March 2009

Macroscopic crack growth rates, da/dN, have been obtained as a function of the stress-intensity factor range, ΔK, for Type 2219-T851 aluminum in ambient air at load ratios, R, of 0.1 and −1. Microscopic modes of crack extension were also determined by transmission electron fractography. Fatigue striation spacings, S, compared well with da/dN when static fracture modes—primarily dimpled rupture—did not occur. These static fracture modes were more prevalent during tension-tension loading at R = 0.1 than during tension-compression loading at R = −1, and they contributed to higher growth rates at the positive load ratio. The relationship between striation spacing and ΔK/E (where E is the elastic modulus) in Type 2219-T851 aluminum was found to be similar to those for other engineering alloys. This relationship was observed to be much less sensitive to changes in the load ratio than the relationship between da/dN and ΔK.
A Test Method to Determine the Degree of Embrittlement in Electrodeposited Copper
Authors: Zakraysek L
Published: March 2009

The brittle fracture of copper conductors in printed circuits is a severe problem in the electronics industry because such fractures will cause open-circuit conditions to occur in completed assemblies where the contributed value is high. In addition, repair possibilities may be limited due to the complexity of the assembly at the time that failures are discovered.

This paper deals with the development of a test method that is useful for the detection of an embrittled condition in foil prior to its application in circuits. Through the use of the mini-cup test method, a ductile-to-brittle transition was discovered, and, through further study of the transition phenomenon, procedures have been suggested for the characterization of electroplated copper foil.
Influence of Various Parameters on the Determination of the Fatigue Crack Arrest Threshold
Authors: Amzallag C , Rabbe P , Bathias C , Benoit D , Truchon M
Published: March 2009

This report presents the results of a round-robin work on the fatigue crack arrest threshold (ΔKth) of 2618 aluminium alloy and AISI 316 steel. The main purpose was to develop a method for the determination of ΔKth, and to examine the influence of various test parameters on this threshold. Among the parameters considered, only the load ratio (R) and the environment (vacuum) appear to have a significant influence on very slow fatigue crack growth rates (FCGR). Moreover, while the results obtained with the 316 steel show a great scatter, the importance of the adopted procedure is pointed out.
An Assessment of A-C and D-C Potential Systems for Monitoring Fatigue Crack Growth
Authors: Wei RP , Brazill RL
Published: March 2009

Electrical potential techniques for crack length measurements have been used for over 15 years to monitor subcritical crack growth. These techniques, based on the changes in electrical resistance of a specimen with crack extension, utilize either a d-c or, more recently, an a-c measurement system. The d-c and a-c systems are described, and the operating characteristics of two specific systems are discussed. A description of the empirical calibration of a specimen using these systems is included. Operating data are included for crack length measurements in a steel compact tension specimen. The d-c system, operated at a current of 10 A, had a crack length resolution of 0.013 mm. The a-c system, employing a lock-in amplifier as a tuned amplifier to provide noise rejection, can be operated at a much lower current of 0.75 A and provided a crack length resolution of 0.010 mm. By design, the a-c system would reject thermal (d-c) electromotive force introduced into the measurement circuit, whereas the d-c system had no such capability. Both systems, however, would be sensitive to changes in resistivity of the material with temperature. In materials of high magnetic permeability, alternating current is not uniformly distributed through the specimen thickness and tends to be concentrated near the specimen surface. The consequences of this “skin effect” in relation to crack length measurements are discussed. Operating procedures that assist in reducing noise and improving measurement sensitivity in both systems are described.
The Use of Fatigue Crack Growth Technology in Fracture Control Plans for Nuclear Components
Authors: Bamford WH , Jones DP
Published: March 2009

The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code now suggests the use of fatigue crack growth analysis in the evaluation of indications found during in-service inspection of nuclear components. In this paper the role of crack growth analysis in the evaluation process is reviewed in some detail, and the background and philosophy of its implementation is discussed.

Each of the steps in the crack growth analysis process is discussed in order to point out the assumptions possible and their implications. A detailed consideration of crack shape change during growth is presented, as well as a statement of guidelines for choosing a reference crack growth law.

The ASME approach is compared with the approaches taken in other industries and, finally, a number of areas in need of further work are highlighted.
Bolted Field Repair of Graphite/Epoxy Wing Skin Laminates
Authors: Bohlmann RE , Renieri GD , Libeskind M
Published: March 2009

Bolted field repair techniques have been developed for AV-8B and F-18 aircraft graphite/epoxy monolithic wing skin laminates up to 12.7 mm (0.5 in.) thick with through-the-thickness damage near and at substructure. Damage sizes to 101.6 mm (4.0 in.) in diameter have been repaired by mechanically fastening a titanium patch to the laminate using blind fasteners in single shear. Repairs were performed with access only to outer surface. Allowables needed for repair design were developed by test for strains at the edge of damaged hole, tension/bearing interaction, and joint shear strength. The capability of an interactive bolted repair analysis computer program (BREPAIR) is also presented. The BREPAIR can define patch geometry and fastener requirements in considerably less time than conventional finite element modeling. Strain predictions correlate well with experimental results. Static tension tests verified that the mechanically fastened repair patch restores the strain capability of the damaged skin to a gross failure strain that exceeds the 4000 μmm/mm design goal. Residual strength tests after four lifetimes of spectrum fatigue also exceed the design goal strength.
Bolt-Bearing Fatigue of a Graphite/Epoxy Laminate
Authors: Crews JH
Published: March 2009

Graphite/epoxy laminates (T300/5208) were tested under bolt-bearing loads for a range of bolt clampup torques and for several test conditions involving water. High clampup torque improved both the static strength and fatigue limit by about 100 percent compared to a simple pin-bearing case, which had no through-the-thickness constraint. The static strength improvement was explained in terms of failure modes. Bolt clampup also influenced the hole elongation that developed before failure. For both the static and fatigue tests, the hole elongations were much larger for the low-torque-clampup case than for the pin-bearing case or for tests with moderate clampup torques. Tests in water degraded static bearing strength only slightly, but reduced the fatigue limit about 40 percent below that for tests conducted in air.
Failure Analysis of Composite Laminates with a Fastener Hole
Authors: Soni SR
Published: March 2009

Stress and strength analysis of composite laminates with a through-the-thickness circular hole under uniaxial tensile load has been conducted. The hole is filled with a rigid core simulating a bolt. As a representation of the force at the bolted joint, displacement boundary conditions are applied to the rigid core. The stress analysis is based on treating the laminate as a homogeneous plate using a finite element technique. The strength analysis is based on the tensor polynomial failure criterion applied to each ply. The ultimate laminate failure strength is based on the last ply failure stress. The resulting predictions of strength are found to be conservative as compared to experimental values.
Design Data for Graphite Cloth Epoxy Bolted Joints at Temperatures up to 450 K
Authors: Bailie JA , Duggan MF , Bradshaw NC , McKenzie TG
Published: March 2009

Results of a design data development program involving hundreds of graphite epoxy bolted joint tests are summarized. Emphasis was on obtaining information for HMF330C/34 cloth material at room temperature, 394, and 450 K; however, many specimens made from T300/5208 and AS/3501 tape laminates were tested to provide correlating information on bearing behavior and the importance of hole-bolt tolerances. Bearing strengths for quasi-isotropic laminates made from these three prepregs were similar. Complete removal of bolt torque was shown to reduce the bearing strength relative to fully torqued bolts by approximately 40 percent. Multiple bolt joints were tested using three different hole-bolt tolerances. Resulting strengths were encouragingly similar, indicating the materials were less brittle than might have been expected. This was particularly true for bearing failures. Loaded-bolt and open-hole tests on cloth laminates indicated a greater degree of effective ductility than indicated by available data for similar tape laminates. Layups with no 45-deg plies exhibited markedly greater brittleness than their quasi-isotropic brethren. The higher the temperature, the less was the ductility for both layups. Bolt head details were shown to exercise a strong influence on bearing strength for single lap joints.
A Toxicity Test Using Life Stages of Champia parvula (Rhodophyta)
Authors: Steele RL , Thursby GB
Published: March 2009

A static-renewal, 11- to 14-day toxicity test has been developed using the life cycle of the marine red alga Champia parvula (C. Ag.) Harv. It measures the vegetative growth, formation of tetrasporangia (meiosis), and formation of cystocarps (sexual fusion). The procedure has been tested with silver, copper, cadmium, lead, and cyanide. The maximum acceptable toxicant concentration (MATC) ranges were calculated for vegetative growth of females and tetrasporophytes and for production of tetrasporangia based on statistically significant differences. The MATCs were determined for sexual reproduction using the presence or absence of cystocarps to measure significance; this yielded MATC values similar to those determined by the other parameters. However, sexual reproduction was the most sensitive of the four end points examined because it dealth with absolute absence rather than statistical differences. The toxicity test with C. parvula is a relatively fast, simple, and inexpensive procedure for testing the effects of toxicants on growth and reproduction in macroalgae. All phases of the life cycle can be maintained in the laboratory (available year round) and can be exposed simultaneously. The results from tests with heavy metals and cyanide indicate that this procedure is comparable to the most sensitive marine animal chronic tests.
Differential Sensitivity of New Versus Mature Synthetic Microcosms to Streptomycin Sulfate Treatment
Authors: Kindig AC , Conquest LL , Taub FB
Published: March 2009

Small, 3-L batch microcosms with synthetic medium and sediment, eight algal species, Daphnia magna, Hyallela, Cyprinotus, rotifers, and protozoa were used to determine whether newly established systems were more sensitive to weekly perturbations of 10 mg/L streptomycin sulfate additions than aged (nutrient-depleted) microcosms. Changes in population densities and pH were contrasted for the microcosms treated after 77 days of maturation and those treated immediately after assembly. Competitive dominance reversals of the algae Ankistrodesmus and Scenedesmus were observed with treatment in the new, but not the aged, microcosms. For all but one diatom species, greater differences were observed with treatment in the younger microcosms. Independent t-tests of the new and aged microcosms revealed a greater number of significant changes in the new microcosms during the 35-day period following initiation of treatment.
Field Investigations and On-Site Toxicity Testing: An Assessment of Habitat Suitability—Arkansas River, Pueblo, Colorado
Authors: Keefe DF , Nimmo DWR , Baldridge D , Iley G
Published: March 2009

An on-site bioassay and aquatic ecological survey were conducted on the Arkansas River near Pueblo, CO. A mobile bioassay trailer was used to test the toxicity of sewage treatment plant (STP) effluent using Arkansas River water for dilution. The aquatic survey was conducted upstream and downstream of the STP's outfall. This study was conceived in accordance with the intent of the U.S. Environmental Protection Agency's (EPA) site-specific water quality criteria guidelines, which recognize that national criteria may not be applicable to species in specific bodies of water because of biological, chemical, and physical variables.

Flow-through tests were conducted using bluegill sunfish (Lepomis macrochirus), fat-head minnow (Pimephales promelas), and a daphnid (Daphnia magna). Standard field and laboratory techniques were used to evaluate physical and biological components of the stream ecosystem. The physical components included flow, substrate, and qualitative fishery habitat description, and the biological components included benthic macroinvertebrate densities, diversity calculations, and fish population surveys.

The results of the bioassay tests generally indicated the following: (1) there were distinct differences in species'; sensitivity to the effluent (that is, the sensitivity was bluegills > fathead minnows > daphnid); (2) the required dissolved oxygen (DO) concentrations in the test tanks were difficult to maintain even though the flow-through rate was increased to four times that required by protocol; (3) the toxicity of the postchlorinated/dechlorinated effluent was less than that of the prechlorinated effluent; (4) no single pollutant could be targeted as the toxic fraction, however, concentrations of chlorine, cyanide, copper, and zinc were at or near LC50 values for the test organisms.
Changes in the Fish Community of the Wabash River Following Power Plant Start-Up: Projected and Observed
Authors: Gammon JR
Published: March 2009

The changes in population trends of fish in the Wabash River resulting from the introduction of thermal effluents were examined for a 14-year period from the standpoint of whether the observed changes could have been predicted from the results of laboratory determinations of thermal tolerance alone. It was concluded that gross changes in community structure could have been predicted but the degree to which most species populations and the community as a whole were influenced would require further detailed information about (1) the chemical and physical characteristics of the environment and (2) the attributes of the resident biota in terms of behavioral responses, physiological capabilities, and life history requirements.
Effect of Cadmium on Lake Water Bacteria as Determined by the Luciferase Assay of Adenosine Triphosphate
Authors: Seyfried PL , Horgan CBL
Published: March 2009

A firefly luciferase assay of bacterial adenosine triphosphate (ATP) was developed to measure the toxic effects of cadmium ions on aquatic organisms. Toxicity was monitored using intracellular (I/C) ATP (in micrograms per litre) as well as plate counts (colony-forming units per millilitre). The bacteria, which belonged mainly to the families Enterobacteriaceae and Pseudomonadaceae, exhibited varying degrees of resistance to up to 100 ppm cadmium when grown in a glucose-salts medium at pH 6.8. Among the organisms tested, cadmium resistance decreased in the following order: Pseudomonas vesicularis > P. aeruginosa > Enterobacter sp. > P. fluorescens > Chromobacter sp. > Serratia sp. A rise in the pH of the growth medium from 5 to 7 resulted in increased toxicity of cadmium.
Effect of Chromium on Larval Chironomidae as Determined by the Optical-Fiber Light-Interruption Biomonitoring System
Authors: Batac-Catalan Z , White DS
Published: March 2009

An optical-fiber light-interruption biomonitoring system for examining the activity of aquatic invertebrates has been developed to test potential toxicity of chromium and other compounds on tubicolous larval Diptera (Chironomidae). Chromium has been identified as a heavy metal of environmental concern, but little is known of its effect on aquatic biota at chronic or sublethal levels. When movement patterns of midge larvae, Chironomus tentans, are monitored by the system, three distinct phases are revealed: respiratory undulations, crawling-type movements, and rest or immobility. It has been shown in other studies that the rates and duration of movements are controlled by dissolved oxygen (DO) levels and temperature. Chromium alters the duration but not the rates of the three movement phases. At 0.01 ppm chromium, larval movement patterns were not altered. At 0.1 and 1.0 ppm, the duration of the respiratory phase was suppressed. Levels from 10.0 to 1000.0 ppm progressively increased the duration of this phase. The 48-h EC50 for fourth instar larvae was calculated to be 61.0 ppm chromium, which shows that the change in respiratory movements does indicate potential lethality of the solutions. Thus, the biomonitoring system's sensitivity is apparent in detecting low-level effects of a heavy metal on this aquatic invertebrate.
Interlaboratory Comparison of a 28-Day Toxicity Test with the Polychaete Neanthes arenaceodentata
Authors: Pesch CE , Hoffman GL
Published: March 2009

An interlaboratory comparison of toxicity tests with the polychaete Neanthes arenaceodentata was conducted to determine the amount of variability expected with this test. Six laboratories each conducted two 28-day flow-through tests, one with silver [as silver nitrate (AgNO3)] as the toxicant and the other with the pesticide endosulfan. Muffled sand (from nonpolluted beaches) was used as sediment in the tests. The mean 28-day median lethal concentrations (LC50s) (based on measured concentrations) for the participating laboratories were 165 ± 52 µg/L and 106 ± 24 µg/L for the tests with silver and endosulfan, respectively. The ratio of the highest to the lowest LC50 value was 2.23 for silver and 1.81 for endosulfan. Therefore, the variability between laboratories was low for this test with N. arenaceodentata.
Development and Validation of an In Situ Fish Preference-Avoidance Technique for Environmental Monitoring of Pulp Mill Effluents
Authors: McGreer ER , Vigers GA
Published: March 2009

A novel in situ technique for studying the vertical preference-avoidance behavior of fish exposed to industrial pollutants was field tested in a three-year program to monitor the effects of sulfite mill effluent (SME) in a remote West Coast fjord. A number of parameters related to the operation of the preference-avoidance cages were investigated, including different fish species, response time, reproducibility, and relationship of avoidance behavior to water quality variables. Comparative tests with juvenile stickleback (Gasterosteus aculeatus), herring (Clupea harengus pallasi), and chum salmon (Oncorhynchus keta) showed that the juvenile salmonids provided the most consistent preference-avoidance response. The response time for determining fish avoidance in the cages was less than 0.5 h. The zone of influence for the SME defined by the preference-avoidance response extended to 10 km down inlet from the mill. Dissolved oxygen and pH were shown statistically to be the most significant (P < 0.05) water quality variables in explaining the vertical distributions observed. Monitoring over a three-year period indicated a reduction in the SME zone of influence coincident with the mill pollution abatement program. It was concluded that the vertical preference-avoidance technique was a sensitive, reliable, and cost-effective monitoring tool.
Toxicity of the Herbicide Endothall to Juvenile Chinook Salmon (Oncorhynchus tshawytscha)
Authors: Liguori VM , Zakour HR , Landolt ML , Felton SP
Published: March 2009

Endothall (7-oxabicyclo-2,2,1-heptane-2,3-dicarboxylic acid) is a contact herbicide which has been approved by the U.S. Environmental Protection Agency (EPA) for use in programs aimed at controlling nuisance organisms such as Eurasian water milfoil (Myriophyllum spicatum). Milfoil has become such a problem in local freshwater systems that Seattle authorities have approved the use of endothall in circumstances in which other eradication methods are not effective. This study was performed to determine the toxicity of endothall to juvenile chinook salmon (Oncorhynchus tshawytscha) and the effects of the herbicide on the ability of this anadromous fish to enter seawater.

Two 14-day flow-through toxicity tests were conducted using nominal concentrations of endothall ranging from 0 to 105.7 ppm of acid equivalent. Four-day toxicity tests were also conducted using the two lowest concentrations (1.5 and 3.0 ppm) to approximate the recommended treatment levels. Upon termination of the toxicity tests, the fish that had been exposed to a noeffect (no mortalities) concentration of the herbicide (≤55 ppm) were utilized in the seawater entry tests.

The 14-day LC50 was calculated to be 62.5 ppm. The seawater entry test proved to be the more sensitive indicator of toxicity, as the fish that had been exposed to endothall levels as low as 3 ppm for four days died when placed in seawater. Survival of the control fish and the fish exposed to 1.5 ppm was acceptable, as was survival of all the fish transferred to clean fresh water. Some behavioral and gross anatomical changes were observed, and histopathological examination revealed hypertrophy of branchial epithelial cells in the fish exposed to 10 ppm or more of endothall.
Column Leach Testing of Solid Industrial Wastes
Authors: Darcel FC
Published: March 2009

Column leach tests with distilled water have been used routinely over the past four years to assess the leachability of industrial wastes. Most tests are run using unsaturated flow condition with three cuts of leachate obtained over 24, 48, and 72 h. Leachate cuts are analyzed for concentrations of inorganic ions, phenols, dissolved organic carbon, conductivity, and pH. It is shown that in many situations ionic and organic flux over the three cuts follow the penetration theory of diffusivity. The relationship held over a wide range of types of waste and initial pollutant concentration. Some bag-house dusts and mine tailings were found to be highly leachable even with distilled water.

Some tests were run using distilled water saturated with carbon dioxide to provide weak acidic conditions. The water leach is followed by 0.1 N acetic acid to simulate the effect of co-disposal with municipal waste.

Some wastes were tested using the Extraction Procedure (EP) test of the U.S. Environmental Protection Agency (EPA).
Closure of an Industrial Waste Site Using a High-Strength Geotextile
Authors: Williams CE
Published: March 2009

The evaluation of the potential hazard of an existing industrial waste site and the design of a unique closure plan for the site are presented in this paper. A high-strength geotextile or woven synthetic fabric is used to enable placement of an earthen cap on the very weak waste body. Specification of appropriate test standards and results are critical for selection of the proper geotextile. Observation of installation procedures and behavior of the geotextile in the field make it possible to draw conclusions concerning needed modifications in standards presently used to select high-strength geotextiles for soft-ground construction.
Enhancement of Aflatoxin B1 Hepatocarcinogenesis in Rainbow Trout (Salmo gairdneri) Embryos by Prior Exposure of Gravid Females to Dietary Aroclor 1254
Authors: Hendricks JD , Stott WT , Putnam TP , Sinnhuber RO
Published: March 2009

Gravid female rainbow trout were exposed to dietary Aroclor 1254 [polychlorinated biphenyl (PCB)] for 2 months before spawning in order to deposit PCB in the lipid of the eggs. Levels of PCB in the eggs were measured, effects of PCB on liver tumor incidence initiated by embryo exposure to aflatoxin B1 (AFB1) were noted, and hepatic mixed-function oxidase (MFO) enzyme activities were determined.

Gas chromatography showed that PCB was present in the lipids of the eggs at significantly higher levels than the background levels present in control eggs. Liver carcinoma incidence was significantly higher in the offspring from the PCB-exposed female at both 9 months (24 out of 40 versus 15 out of 40) (P < 0.025) and 12 months (53 out of 57 versus 39 out of 59) (P < 0.001), which indicates that preinduction of the liver by PCB enhances aflatoxin-initiated carcinogenesis. Mixed-function oxidase determinations also revealed trends that suggest induction of the MFO system by PCB. The cytochrome P-450 content in the PCB fry livers was 174 percent of the control values, whereas the in vitro conversion of AFB1 to aflatoxicol (AFL) was 264 percent of that of the control. These results call attention to the possible role of PCB in enhancing carcinogenesis.
On-Site Critical Life-Stage Bioassay with the Fathead Minnow, Pimephales promelas, on Effluent from the Wastewater Treatment Facilities of Austin, Minn.
Authors: Iwan GR , Cella GE
Published: March 2009

An on-site, flow-through, critical life-stage bioassay was conducted challenging the fathead minnow with treated effluent from the City of Austin, Minn., wastewater treatment facilities. Using U.S. Environmental Protection Agency (EPA) methodology modified by Union Carbide Environmental Services (UCES) and the Minnesota Pollution Control Agency (MPCA), effluent effect data were obtained for (a) egg hatchability, (b) fry survival, (c) fry growth, and (d) fry deformities. The data were used to estimate the maximum acceptable effluent concentration (MAEC) range, expressed as percent effluent and ammonia concentration. Statistical analyses (P = 0.05) indicated an MAEC range of 18 to 32 percent treated effluent. The corresponding un-ionized and total ammonia concentrations were, respectively, 0.2 to 0.3 mg/litre and 2.3 to 3.2 mg/litre.

In light of the current EPA water quality criterion of 0.02 mg/litre un-ionized ammonia, the results suggest that in situ studies of this type might be useful in establishing more realistic discharge requirements.
A Radiorespirometric Study of the Effects of a Chemical Substance on Carbohydrate Metabolism in the Intact Fish
Authors: Liu DHW
Published: March 2009

The effects of potassium pentachlorophenate (KPCP) on carbohydrate metabolism in the fish (Cichlasoma bimaculatum) were studied using radiorespirometry. Analysis of the patterns of radiolabeled carbon dioxide (14CO2) recovery from fish exposed to 0, 0.2, and 1.5 ppm of KPCP and metabolizing specifically labeled carbon-14 (14C)-glucose and acetate indicated that this species of fish uses the Embden-Meyerhoff-Parnas (EMP), pentose phosphate (PP), and glucuronic acid (GA) pathways in conjunction with the tricarboxylic acid (TCA) cycle for metabolizing carbohydrates. The KPCP stimulated the EMP pathway and the TCA cycle and presumably reduced the utilization of the PP and GA pathways.
Prediction of Ignition Thresholds During Ramp Heating
Authors: Martin SB
Published: March 2009

This paper offers a heuristic, semiempirical approach to prediction of thresholds of spontaneous ignition of materials exposed to ascending heat ramps in terms of the dependence of the time taken to ignite ti on rates of change of heat flux with time. The approach relies on the concept that two conditions are necessary (if not always sufficient) for ignition to occur: (1) the exposing flux must first grow to exceed some critical level Hc, taken as equivalent to the so-called “critical irradiance” determined from constant-flux exposures; (2) the additional time for ignition to occur (ti − tc) is then a prescribable inverse function of the rate of flux increase (that is, the slope of the ramp). Temperature attainment criteria are employed in arriving at a mathematical formalism.

Data to test the approach are derived from a previous experimental study of quarter-scale room fires (propane fueled) in which wood block targets on the floor were observed to ignite spontaneously from exposure to heat radiated by the ceiling. Additional data, acquired specifically to extend the range of rates of flux growth and reported here for the first time, were obtained by exposing similar wood targets to ascending heat ramps produced manually with a tungsten-filament radiant heat source. The resultant data, from the two experimental sources, are reasonably well fit by a thermally thick-solid expression relating ti − tc to the rate of flux growth evaluated with independently derived empirical constants.
Factors Affecting Smoke Production During Combustion of Polyolefin Polymers
Authors: Sutker BJ
Published: March 2009

Fire is only one of the major hazards that result from rapid combustion of polyolefins. Another major hazard is smoke evolution, since smoke can prevent people in a fire from finding necessary exits. Smoke, however, should not be considered independently from the composition of the smoke, that is, the products of combustion.

Olefin polymers are formulated with a variety of additives to meet specific performance characteristics. Smoke can be reduced by additives, but often at the expense of other properties of the system. Suggestions are made for further research activities to improve smoke reduction.

Test methods used to measure smoke are described and comparisons are made between materials in a given test sequence. Further research work is needed in the area of assessing smoke evolution as a function of time, particularly at the onset of a fire.
A Proposed Rating System to Describe the Behavior of Reinforced Plastics in Large-Scale Fire Tests
Authors: Park RE
Published: March 2009

A fire safety rating system for use with fiberglass-reinforced plastics (FRP) is developed in this paper that covers ignition, flame spread, smoke development, and toxicity. The tests chosen for the rating system are described and examples presented of how several different types of FRP sheet perform on these tests. A new class of fire retardant systems offer, for the first time, a combination of low flame spread, low smoke, and low toxicity. Toxicity data are presented on both large-scale (room burn) and small-scale tests.
Nonspill Cage Feeder for Quail
Authors: Brunton RB , Schafer EW
Published: March 2009

A feeding device for quail is described that is small and easy to handle, lightweight, and nonspillable. It holds a 5-day food supply for adult paired coturnix (Coturnix coturnix) and minimizes fecal contamination. Although the feeding device was designed for use with quail in breeding cages, it could be modified for other test situations or bird species.
Plastic Enclosures and Containers for Evaluating the Efficacy and Safety of Pesticides in Aquatic Environments
Authors: Walker CR , Burress RM , Gilderhus PA
Published: March 2009

Enclosures made of plastic sheeting or tubing and large plastic bags placed in aquatic environments have been used to evaluate the efficacy and safety of aquatic pest control agents under actual field conditions. These methods provide for biological replications of field plots and direct comparison of treatment rates and application methods, formulations, timing, and so on. Both efficacy and safety can also be compared by “before” and “after” measurements with positive controls and the option of using both the natural community of the ecosystem and simulated populations introduced in cages or directly to the enclosures. Although plastic bags or cylinders have size limitations, the plastic sheeting can be used to form enclosures of almost any dimension. Results of two field tests are presented to demonstrate the utility of on-site bioassays for determining the concentrations of rotenone needed to eliminate grass carp (Ctenopharyngodon idellus) in ponds and of an experimental piscicide to achieve selective removal of carp (Cyprinus carpio) from a pond containing populations of game fish.
Chapter 3—Design and Performance Standards
Authors: Rowe WD
Published: March 2009

The ASTM Committee on Research and Technical Planning is undertaking an effort to review and clarify the respective roles of design and performance standards in the ASTM voluntary standards operations. This required a broad view of the problem, starting from basic definitions of standards and understanding of how such standards are used both in engineering practice and regulatory utilization. On this basis this chapter analyzes perceptions of: (1) definitions, (2) design and performance standard use considerations, and (3) acceptance and achievement standards and their roles. In carrying out the study a great deal of attention has been given to the basic understanding of how such standards may be used most effectively.
Chapter 11—Applications, Pitfalls, and Alternatives of Medical Device Standards
Authors: Houston MF
Published: March 2009

Litigation is a booming business in the United States. From 1976 to 1980 the number of product liabiHty suits for personal injury commenced in just the federal courts increased every year. In 1980 the number was 7755 new cases, an increase of 26.5% over 1979
Chapter 23—Technology Awareness: Electrical Safety, the Clinical Environment, and Standards
Authors: Hammer GS , Staewen WS , Kagey KS
Published: March 2009

The preceding chapter on labeling suggests the value of individual efforts in health care institutions to correct potential and actual health hazards. The integration of the fields of clinical and hospital engineering in hospital management has brought a new perspective on technology management to the health care industry and the individual institution utilizing this resource. Such in-house efforts offer great promise in developing solutions to recurring problems and raising the quality of care through technology management.