bluuebunny/crossref_metadata_2025 huggingface dataset:
Crevice Corrosion Testing of Austenitic, Superaustenitic, Superferritic, and Superduplex Stainless Type Alloys in Seawater
Authors: Zeuthen AW , Kain RM
Published: March 2009

In industry, many problems from corrosion occurring in crevices have been experienced and reported. These include the refining industry, offshore drilling platforms, fossil and nuclear power plants, chemical plants and the public utilities. The services are highly variable. Corrosion mechanisms and the results experienced are influenced by severe environments which cannot always be avoided.

Corrosion testing is considered useful not only in comparing materials, but also in selecting materials from the design standpoint. The ultimate goal is to use materials which are superior to those currently in use. This will result in fewer outages, reduce repairs and significantly lower costs.

This paper provides the results from four seawater test programs addressing crevice corrosion resistance of a number of “superferritic,” “superaustenitic,” and “superduplex” alloys, along with conventional “300 Series” stainless steel. These programs included exposure to natural fouling organisms which can produce crevices, and testing which comprised several different manmade crevice configurations. Alloys found to be resistant under some test conditions were prone to attack under others. All of the “super stainless” steels were found to be more resistant to crevice corrosion than conventional austenitic grades, but some were susceptible to some degree.
Statistical Analysis of Pitting Corrosion in Condenser Tubes
Authors: Ault JP , Gehring GA
Published: March 2009

Condenser tube failure via wall penetration allows cooling water to contaminate the working fluid (steam). Contamination, especially from brackish or saltwater, will lower steam quality and thus lower overall plant efficiency. Because of the importance of minimizing leakages, power plant engineers are primarily concerned with the maximum localized corrosion in a unit rather than average corrosion values or rates. Extreme value analysis is a useful tool for evaluating the condition of condenser tubing. Extreme value statistical techniques allow the prediction of the most probable deepest pit in a given surface area based upon data acquired from a smaller surface area. Data is gathered from a physical examination of actual tubes (either in-service or from a sidestream unit) rather than small sample coupons. Three distinct applications of extreme value statistics to condenser tube evaluation are presented in this paper: (1) condition assessment of an operating condenser, (2) design data for material selection, and (3) research tool for assessing impact of various factors on condenser tube corrosion.

The projections for operating units based on extreme value analysis are shown to be more useful than those made on the basis of other techniques such as eddy current or electrochemical measurements. Extreme value analysis would benefit from advances in two key areas: (1) development of an accurate and economical method for the measurement of maximum pit depths of condenser tubes in-situ would enhance the application of extreme value statistical analysis to the assessment of condenser tubing corrosion pitting and (2) development of methodologies to predict pit depth-time relationship in addition to pit depth-area relationship would be useful for modeling purposes.
Corrosion Coupon Testing in Natural Waters: A Case History Dealing With Reverse Osmosis Desalination of Seawater
Authors: Kain RM , Adamson WL , Weber B
Published: March 2009

Corrosion testing in natural waters has generally focused on assessing either resistance of materials to corrosion in a given environment or characterizing environmental corrosivity. Sometimes both can be accomplished simultaneously. For example, while the objective of another test program reported in this symposium was to determine the corrosivity of seawater world-wide, the corrosion resistance of three very diverse materials was also identified. In those tests, relatively large specimens (100 mm × 300 mm) were exposed in accordance with ASTM GS2: Standard Practice for Exposing and Evaluating Metals and Alloys in Surface Seawater.

This paper describes a series of corrosion tests performed to determine the general and localized corrosion behavior of two stainless alloys (UNS S31603 and UNS NO8367) and 70/30 CuNi (UNS C71500) in three aqueous environments associated with advanced reverse osmosis (RO) desalination of natural seawater. In addition to seawater (the RO feed stock), the other environments included a 2nd-pass RO brine with lower chloride content and total dissolved solids man raw seawater, and an ultrapure 3rd-pass permeate.

Two ASTM standards were reviewed for guidance in the design of the experiment Since testing could be conducted in an operating prototype RO system, the test program followed the general procedures for an in-plant corrosion tests described by ASTM G4-95: Standard Guide for Conducting Corrosion Coupon Tests in Field Applications. This standard, along with G78- 95: Standard Guide for Crevice Corrosion Testing of Iron-Base and Nickel-Base Alloys in Seawater and Other Chloride-Containing Environments, provided guidance in the selection of test specimens and mounting fixtures as well as crevice formers utilized. The G78-9S standard guide also provided considerations associated wim the interpretation of the crevice corrosion test results.
Comparison of Current Reversal Chronopotentiometry (Crc) And Small Amplitude Cyclic Voltammetry (Sacv) Method To Determine The Long-Term Corrosion Tendency Of Copper-Nickel Alloys in Polluted And Unpolluted Seawater Under Jet-Impingement Conditions
Authors: Reda MR , Alhajji JN
Published: March 2009

The cyclic current reversal chronopotentiometry (CRC) technique is utilized to determine the long-term corrosion tendency of UNS C70600 and UNS C71500 copper-nickel alloys in sulfide polluted and unpolluted seawater. The CRC results were compared with the corrosion tendency obtained by the modified linear polarization method Small Amplitude Cyclic Voltammetry (SACV) over a long exposure time and the results are in agreement for both C70600 and C715OO alloys. This contradicts the conclusions on the effects of sulfide on copper-nickel alloys by many previous investigators who misinterpreted the sharp active shift in potential as an indication of increase in corrosion rate. For an active/passive alloy such as C71500 a higher amplitude current per cycle is required (e.g. 100 μA/20 seconds) in the CRC method and under jet-impingement conditions, while a lower amplitude current per cycle (e.g. lμA/20 seconds) is required for an alloy that does not exhibit active/passive behavior. The CRC technique was found to be unsuccessful in screening out the long-term corrosion tendency of copper alloys in polluted and unpolluted sea water and under stagnant or stirred conditions (i. e. non-jet-impingement conditions).
Simulation Methods for Life and Remaining Strength Prediction of High-Temperature Polymeric Composites Subjected to Cyclic Loads
Authors: Case SW , Plunkett RB , Reifsnider KL
Published: March 2009

The purpose of this paper is to establish and demonstrate a methodology for the prediction of the remaining strength and life of polymer-based composite laminates subjected to cyclic and sustained thermomechanical conditions. Conditions to be considered include elevated temperature (in air) and cyclic (fatigue) loading at various stress levels. The approach taken is to construct a simulation of the damage accumulation process and failure mode that controls the remaining strength and life for carbon fiber-reinforced K3B polymer matrix systems. The simulation is based on micromechanical and ply-level models of composite strength that combine the properties, geometry, and arrangement of the constituents to estimate the global strength as a function of those parameters. As applied conditions influence those parameters, those influences are combined to yield estimates of the remaining strength and life (when global strength is reduced to the level of the applied conditions). These predicted values for the remaining strength as a function of the number of fatigue cycles, temperature, and load level are in good agreement with available experimentally measured values.
The Effects of Moisture on the Material Properties and Behavior of Thermoplastic Polyimide Composites
Authors: VanLandingham MR , Eduljee RF , Gillespie JW
Published: March 2009

Thermoplastic polyimides are a relatively new class of polymers that exhibit high-temperature stability and are useful in composite applications. One such material is Avim-id® K3B reinforced with Magnamite® IM7 graphite fibers. This composite system exhibits excellent strength and toughness, retains its strength and toughness after prolonged exposure to elevated temperatures, and resists microcracking at extremely low (liquid nitrogen) temperatures. Further characterization of IM7/K3B thermoplastic composites is focused on evaluating hygrothermal effects on the material properties and behavior. The environmental conditioning test matrix includes three temperatures (20, 40, and 80°C) and four relative humidity levels (75, 85, 97, and 100%). Observations and conclusions from these studies include the following: (1) the moisture diffusivity of IM7/K3B has a classic Arrhenius dependence on temperature; (2) the moisture saturation level depends on the relative humidity level to the power of 1.34 with a maximum value of 0.55% by weight; (3) the glass transition temperature Tg is lowered with moisture absorption but is recovered when the sample is redried; (4) the intralaminar fracture toughness GIc remains constant after extensive hygrothermal conditioning; (5) the diffusion kinetics are Fickian in general, except for a few non-Fickian anomalies that are related to development of transverse microcracks.
Microscopic Study of Surface Degradation of Glass Fiber-Reinforced Polymer Rods Embedded in Concrete Castings Subjected to Environmental Conditioning
Authors: Bank LC , Puterman M
Published: March 2009

The surface degradation of glass fiber-reinforced polymer (GFRP) pultruded rods when embedded in concrete castings and subjected to environmental conditioning is discussed in this paper. Investigation of the degradation of the GFRP rods was performed using optical microscopy and scanning electron microscopy (SEM). Unidirectionally reinforced pultruded rods (6.3- and 12.7-mm diameters) containing E-glass fibers in polyester and vinylester matrices were conditioned at standard laboratory conditions (21°C, 65% relative humidity) or submerged in aqueous solutions (tap water) at 80°C for durations of 14 and 84 days. Observations of the surfaces and cross-sections of the rods by optical microscopy and SEM revealed a variety of degradation phenomena. Embedded hygrothermally conditioned rods were found to have developed surface blisters of different sizes and depths. SEM studies of the surface revealed degradation of the polymer matrix material and exposure and degradation of the fibers close to the surface of the rods. The rods with the vinylester resin matrix showed less extensive degradation than those with the polyester resin matrix; however, the degradation characteristics of the two types of rods appear to be similar.
Use of Thermogravimetric Analysis to Develop Accelerated Test Methods to Investigate Long-Term Environmental Effects on Fiber-Reinforced Plastics
Authors: Prian L , Pollard R , Shan R , Mastropietro CW , Gentry TR , Bank LC , Barkatt A
Published: March 2009

The development of accelerated test methods to characterize long-term environmental effects on fiber-reinforced plastics (FRPs) requires the use of physicochemical methods, as well as macromechanical measurements, in order to investigate the degradation processes and predict their course over long periods of time. Thermochemical and mechanical measurements were performed on a large number of FRPs exposed to neutral, basic, and acidic media between 23 and 80°C over periods of 7 to 224 days. The resin matrices used in the present study included vinylester, polyester, and epoxy, and the fiber materials were silicate glass, aramid, and carbon. TGA was used to study the effects of aqueous media on FRPs. In particular, the relative weight loss upon heating the previously exposed material from 150 to 300°C was found to be indicative of the extent of matrix depolymerization. Indications were obtained for correlation between this weight loss and the extent of degradation of various measures of mechanical strength. The measured weight change of the tested materials during exposure was found to reflect the extent of water absorption and could be related to the extent of the weight loss between 150 and 300°C. In basic environments, weight loss, rather than gain, took place as a result of fiber dissolution. Among various FRPs, those with aramid fibers were found to be especially prone to degradation due to extensive water uptake. Basic environments caused a large decrease in strength due to fiber dissolution. Acetic acid buffers caused significant matrix depolymerization. Raising the temperature to 80°C appeared to be the most effective method of enhancing the degradation effects, as reflected in both the thermochemical and mechanical data. Furthermore, the trends observed at 80°C (for example, with respect to solvent effects) were identical with the trends observed at lower, service-like temperatures. Thus, elevating the temperature is a promising acceleration factor. In agreement with the enhanced matrix depolymerization observed in the TGA measurements, higher temperatures also caused a decrease in Tg, as measured by DSC.
Development of Antibodies to Teleost Vitellogenins: Potential Biomarkers for Environmental Estrogens
Authors: Denslow ND , Chow MM , Folmar LC , Bonomelli SL , Heppell SA , Sullivan CV
Published: March 2009

We describe 2 IgG class and an IgM class onoclonal antibodies and a polyclonal antiserum which recognize a wide variety of teleost vitellogenins. Based on these and previous results we discuss the potential for developing a “universal” ELISA to recognize all vertebrate vitellogenins.
Protein Patterns and Toxicity Identification Using Artificial Neural Network Models
Authors: Bradley BP , Brown DC , Iamonte TN , Boyd SM , O'Neill MC
Published: March 2009

Proteins extracted, separated, and visualized can provide detailed information about an organism and its environment. We have used an artificial neural network model to identify significant exposures of a cladoceran (Daphnia magnet) to alcohol and pesticides, of a copepod (Eurytemora affinis) to heat and salinity, of an earthworm (Lumbricus terrestris) to sulfur mustard and of a small fish (Oryzias latipes) to groundwater concentrations. The method depends on systematic differences or tendencies in numbers and amounts of proteins present in different treatments or environments. We illustrate how neural computing might be useful in retrieving the information contained in the hundreds or thousands of proteins expressed in test organisms. Such information could apply to prediction of toxicity, identification of toxicity and to characterizing environments in general.
Chromosome Translocations Measured by Fluorescence In-Situ Hybridization: A Promising Biomarker
Authors: Lucas JN , Straume T
Published: March 2009

A biomarker for exposure and risk assessment would be most useful if it employs an endpoint that is highly quantitative, is stable with time, and is relevant to human risk. Recent advances in chromosome staining using fluorescence in situ hybridization (FISH) facilitate fast and reliable measurement of reciprocal translocations, a kind of DNA damage linked to both prior clastogenic exposure and to risk. In contrast to other biomarkers available, the frequency of reciprocal translocations in individuals exposed to whole-body radiation is stable with time post exposure, has a rather small inter-individual variability, and can be measured accurately at the low levels. Here, we discuss results from our studies demonstrating that chromosome painting can be used to reconstruct radiation dose for workers exposed within the dose limits, for individuals exposed a long time ago, and even for those who have been diagnosed with leukemia but not yet undergone radiotherapy or chemotherapy.
Quantification of Dna Adducts in Small Fish Exposed to Alkylating Agents
Authors: Law JM , McMillin DJ , Swenson DH , Means JC
Published: March 2009

It is widely believed that most chemical carcinogens act by binding to cellular genetic material and causing somatic mutations. Chemical modification of DNA (e.g., the formation of DNA adducts) is the first in a series of stages that lead to mutation, cell transformation, and tumor development.

Sensitive methods for detection of DNA adducts are essential for mechanistic studies of mutagenesis and carcinogenesis and for biomonitoring of populations at risk for environmentally caused cancer. DNA adducts may be detected with such methods as 32Ppostlabeling, immunoassays, HPLC with fluorescence detection, and gas chromatography/mass spectrometry, with varying degrees of sensitivity and structural specificity. Alkylation at the N-7 position of guanine is a preferential site of attack for most alkylating agents, but may be of little biological consequence, while adduct formation at the O6 position of guanine (less common) is most highly correlated with carcinogenesis.

We have examined the suitability of western mosquitofish (Gambusia affinis) as a native sentinel species for monitoring environmental exposures to mutagens and carcinogens. Mosquitofish are a native species to the U.S. and are also widely distributed in warm waters throughout the world. These fish are ideal for monitoring local exposures because they are non-migratory and are found in a wide variety of habitats. In the laboratory, they are easily cultured using techniques developed for other small fish species and appear resistant to infectious diseases. Thus, methods may be directly assessed under controlled conditions before being applied to field situations.

In these studies, mosquitofish were exposed to a model alkylating agent, methylazoxymethanol acetate, at 10 ppm in the ambient water for 2 h. Fish were then transferred to clean water and held for up to 72 h. Livers were excised, pooled for 5 fish, and DNA was extracted and prepared for analysis. Liver DNA extracts were assessed for levels of N-7 and O6-methylguanine by isotope dilution GC/mass spectrometry, using deuterated analogs of methylguanine adducts as standards. Detection limits for the assay were approximately 1.6 femtomoles of adduct per mg DNA (about 1 adduct per 2 million bases). Approximately 55–185 pg (330–1100 femtomoles) O6 -methylguanine per mg DNA were measured in exposed fish in the first 72 h after exposure. These lesions were correlated with a 33% liver tumor incidence after 25 weeks in parallel experiments.
Genotoxicity of Model and Complex Mixtures of Polycyclic Aromatic Hydrocarbons
Authors: Donnelly KC , Phillips TD , Onufrock AM , Collie SL , Huebner HJ , Washburn KS
Published: March 2009

Polycyclic aromatic hydrocarbons (PAHs) are one of the most ubiquitous classes of environmental carcinogens; however, limited information is available to describe their potential genotoxic interactions. This manuscript reports on the interactions of PAHs in complex mixtures as determined in microbial mutagenicity assays. Samples analyzed included separate 2-, 3-, and 4-ring PAH individual model fractions (IMFs) constructed to simulate the composition of a model coal tar. These were tested individually and in various combinations, including a reconstituted model fraction (RMF) composed of all three IMFs. A solvent extract of coal tar and a benzo(a)pyrene-amended extract of coal tar were also tested. The maximum mutagenic response of 1,089 revenants was induced by the RMF at a dose of 90 μg/plate with metabolic activation. At the four lowest dose levels, the response observed in the RMF sample was increased when compared to the 4-ring-IMF sample alone. However, the response observed with the RMF sample at the highest dose tested (900 μg/plate) was less than was observed in the 4-ring-IMF sample tested independently. When IMF samples were combined or mixed with individual chemicals, some inhibition was observed. These data indicate that mixtures of PAHs can exhibit a variety of mutagenic interactions controlled by both the metabolism of the PAHs and by their concentration in the mixture. This research was supported by NIEHS Grant No. P42-ES04917.
Development and Characterization of an Elisa for trans-3-Hydroxycotinine, a Biomarker for Mainstream and Sidestream Smoke Exposure
Authors: Rees WA , Kwiatkowski S , Stanley SD , Granstrom DE , Yang JM , Gairola CG , Drake D , Glowczyk J , Woods WE , Tobin T
Published: March 2009

trans-3-Hydroxycotinine is the major urinary metabolite of nicotine in man and can serve as an important biomarker of tobacco smoke exposure. A sensitive ELISA test for trans-3-hydroxycotinine was developed with an I-50 for this nicotine biomarker of between 1.0–3.0 ng/ml. This ELISA test has about 10 fold less affinity for cotinine and 1000-fold less affinity for nicotine and other nicotine metabolites. No matrix effects were detectable in human saliva and relatively small matrix effects (I-50 for trans-3-hydroxycotinine, about 25 ng/ml) in urine was observed. The assay readily detected levels of apparent trans-3-hydroxycotinine in urine samples from smoke-exposed mice and rats. This ELISA is therefore a sensitive test for the determination of trans-3-hydroxycotinine in plasma, saliva, and urine samples from humans and animals, and can be used to monitor exposure to tobacco smoke or nicotine.
Utilizing Biomarker Techniques: Cellular Membrane Potential as a Biomarker of Subchronic Toxicity
Authors: Fort DJ , Stover EL , Burks SL , Atherton RA , Blankemeyer JT
Published: March 2009

A biomarker assay designed to monitor the health of Daphnia sp. as well as evaluate sites of toxicant action was used to study the toxic effects of copper, diazinon, and polyacrylamide. The assay used the uptake of a fluorescent cellular membrane-bound dye and corresponding fluorescence measurement as an early indicator of change in cellular membrane potential. This change in the membrane potential is an indicator of potential cellular stress. Following short-term exposure to the electrochromic dye, di-4-ANEPPS, and the toxicants, fluorescence readings were collected, stored in a database management system, and output for graphical display and statistical analysis. Median inhibitory concentrations (IC50), No Observed Effect Concentrations (NOEC), and Lowest Observed Effect Concentrations (LOEC) values for copper were approximately 52.6, 35.0, and 50.0 μg/L. The approximate IC50, NOEC, LOEC values for diazinon and polyacrylamide were 0.45, 0.25, and 0.50 μg/L; and 350.0, 300.0, and 500.0 μg/L, respectively. Fluorescence microscopy indicated that copper primarily affected the mouth parts (orofacial) and digestive tract. Diazinon, however, primarily caused an effect on the anterior portion of the nervous system. Polyacrylamide appeared to induce toxicity throughout the entire epithelial layer of the Daphnia. These results suggested this assay may be effectively used to monitor for organism stress or toxicity as well as evaluate potential sites of toxic action.
Effect of Low-Level Copper and Pentachlorophenol Exposure on Various Early Life Stages of Xenopus Laevis
Authors: Fort DJ , Stover EL
Published: March 2009

An evaluation of the effects of low-level copper and pentachlorophenol exposure on various early life stages of the South African clawed frog, Xenopus laevis, was performed using stage-specific and long-term continuous exposures. Stage-specific exposure experiments were conducted such that separate subsets of embryos and larvae from the same clutch were exposed to two toxicants, copper and pentachlorophenol, from 0 d to 4 d (standard Frog Embryo Teratogenesis Assay — Xenopus [FETAX]), 4 d to 8 d, 8 d to 12 d, and 12 d to 16 d. Results from two separate concentration-response experiments indicated that sensitivity to either toxicant increased in each successive time period. Longer-term exposure studies conducted for 60 to 75 days indicated that copper, but not pentachlorophenol induced reduction deficiency malformations of the hind limb at concentrations as low as 0.05 mg/L. Pentachlorophenol concentrations as low as 0.5 μg/L inhibited tail resorption. However, copper did not adversely affect the process of tail resorption. These results indicated that studies evaluating longer-term developmental processes are important in ecological hazard evaluation.
Alterations in Chicken Embryonic Development as a Sensitive Indicator of 2,3,7,8-Tetrachlorodibenzo-P-Dioxin Exposure
Authors: Dickerson RL , Hoover JA , Peden-Adams MM , Mashburn WE , Allen CA , Henshel DS
Published: March 2009

2,3,7,8-Tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) exposure may be detected by chemical analysis or by its biological effects on in vivo or in vitro systems. Chemical analysis is expensive and does not give indications of the bioavailability of the material to an organism. Dosing an in vitro system with an extract obtained from an environmental sample has numerous advantages. This method is relatively cheap, quite sensitive, and can be used to generate quantitative dose response relationships as well as quantitative structure activity relationships. One method that is currently being used in our laboratories and others is a whole embryo model which consists of fertile hen's eggs injected on day 0. The eggs are incubated for either 48 or 96 hours and the embryos removed and examined for malformations. In addition, alterations in the vitelline vasculature are examined in the 96 hour embryos. This model is able to detect significant 2,3,7,8-TCDD effects at levels of 2–20 pg/g egg (ppt), depending on the endpoint. The results of this study were compared to results of the H4IIE assay based on EROD induction. Although the H4IIE assay is more sensitive, the egg injection method provides more data on effects.
Evaluating Gross Brain Asymmetry: A Potential Biomarker for 2,3,7,8 Tetrachlorodibenzo-p-Dioxin-Related Neurotoxicity
Authors: Henshel DS , Martin JW , Best D , Cheng KM , Elliott JE , Rosenstein D , Sikarskie J
Published: March 2009

Recent evidence indicates that avian embryonic exposure to polychlorinated dibenzodioxins (PCDDs) and related compounds is associated with the development of a gross brain asymmetry which can be quantified. Three methods can be used to quantify the asymmetry,including external measurements of the intact brain, measurements of brain cross-sections and measurements of computer tomography (CT) - generated images of brain sections. All three methods produce reliable results. The whole brain measurements do not require specialized equipment, and are the most flexible. However, the possibility for unintentional bias is greatest for this technique. The CT scan technology is non-invasive, but requires access to specialized equipment and may be expensive. The cross-sectional measurements, which are similar to the CT scan measurements, require careful processing prior to measurement.
Mysid (Mysidopsis Bahia) Life-Cycle Test: Design Comparisons and Assessment
Authors: Lussier SM , Champlin D , Kuhn A , Heltshe JF
Published: March 2009

This study examines ASTM Standard E1 191-90, “Standard Guide for Conducting Life-cycle Toxicity Tests with Saltwater Mysids”, 1990, using Mysidopsis bahia, by comparing several test designs to assess growth, reproduction, and survival. The primary objective was to determine the most labor efficient and statistically powerful test design for the measurement of statistically detectable effects on biologically sensitive endpoints. Five different test designs were evaluated varying compartment size, number of organisms per compartment, and sex ratio. Results showed that while paired organisms in the ASTM design had the highest rate of reproduction among designs tested, no individual design had greater statistical power to detect differences in reproductive effects. Reproduction was not statistically different between organisms paired in the ASTM design and those with randomized sex ratios using larger test compartments. These treatments had numerically higher reproductive success and lower within tank replicate variance than treatments using smaller compartments where organisms were randomized, or had a specific sex ratio. In this study, survival and growth were not statistically different among designs tested. Within tank replicate variability can be reduced by using many exposure compartments with pairs, or few compartments with many organisms in each. While this improves variance within replicate chambers, it does not strengthen the power of detection among treatments in the test. An increase in the number of true replicates (exposure chambers) to eight will have the effect of reducing the percent detectable difference by a factor of two. The results indicate that, of the five test designs compared, test design two, with randomized sex ratios using larger test compartments, employed the same number of test organisms in fewer compartments, produced good survival and growth, yielded reproduction comparable with the ASTM method, and required less animal handling and monitoring time. We recommend adoption of this test design with the incorporation of an increase in the number of true replicates to eight.
Responses of the Estuarine Plant Scirpus Olneyi to two Herbicides, Atrazine and Metolachlor
Authors: Lytle JS , Lytle TF
Published: March 2009

The phytotoxicity of atrazine and metolachlor was tested using rhizome cultures of Scirpus olneyi, a major salt marsh emergent macrophyte that has wide distribution around Gulf estuaries. A variety of types of exposure media and methods of toxicant addition were employed. Test systems included: (1) rhizomes placed in biochambers with atrazine-spiked “clean” estuarine sediment; (2) rhizomes placed in biochambers containing composited estuarine sediment with grain sizes ranging from sands to clays; (3) young shoots placed in biochambers prepared as in (2); and; (4) young shoots placed in biochambers in seawater diluted to varying salinities. Metolachlor was the test pesticide in systems 2–4. Plant responses measured included peroxidase activity (POD), peroxidation products, chlorophyll, and growth. All responses to atrazine-spiked sediments were clearly related to the dose, whereas responses to metolachlor showed high variability with increasing salinity and low variability with varying grain size. At 12‰, salinity effects completely masked the metolachlor effects (as measured by growth) at all test levels, indicating that growth as an ecological endpoint used to evaluate a chemical stressor is ineffective under certain salinity regimes.
Reducing the Effects of Total Ammonia in 10-Day Sediment Toxicity Tests with the Amphipod, Rhepoxynius Abronius
Authors: Pinza MR , Kohn NP , Ohlroggc SL , Ferguson CJ , Word JQ
Published: March 2009

Sediment toxicity tests are used to measure the effects of contaminants in sediment and are important management tools for agencies that regulate dredging and dredged material disposal, wastewater discharges, and other activities that might affect the aquatic environment. The interpretation of the results of routine toxicity tests can, however, be confounded by naturally occurring factors, such as ammonia, sulfides, sediment grain size, and salinity. Ammonia has been suspected for many years to be a sediment toxicant. It is only recently that the sensitivity of routine test organisms to ammonia has been quantified, and even more recently that dose-responses have been related to ammonia concentrations that occur in standard sediment toxicity tests. The first objective of this study was to compare the effects of ammonia in sediment toxicity tests under two pore water ammonia reduction procedures. The first procedure reduced total pore water ammonia from test sediments by replacing overlying water two times in a 24-h period. The second procedure used natural bacterial processes to reduce pore water ammonia. The second objective was to evaluate the current no-effect concentrations (originally based on 96-h water-only toxicity tests) using the overlying- water-exchange procedure. The final objective was to determine whether ammonia concentrations would increase to toxic levels in sediments that had naturally reached no-effect concentrations, but that were then physically disturbed. The marine amphipod, Rhepoxynius abronius, was exposed to sediments with low (≈30 mg/L), moderate (≈ 100 mg/L), and high (≈200 mg/L) initial concentrations of pore water total ammonia in five separate 10-day toxicity tests. One test followed standard protocols (ASTM E 1367-90). Two tests were initiated after pore water ammonia concentrations were reduced by overlying water exchange to ≤30 mg/L and ≤20 mg/L. Two tests were initiated after pore water total ammonia decreased by natural reduction to <10 mg/L, half of the test chambers from the final test were disturbed by shaking before test organisms were placed in the test containers. Toxicity of sediments with higher initial concentrations of pore water ammonia decreased significantly when ammonia was reduced to ≤30 mg/L. Reaching 30 mg/L required up to 12 days with the reduction procedure (24 exchanges of overlying water) or up to 47 days under the natural-reduction procedure. There was no difference in toxicity between the naturally reduced and the disturbed samples.
A Rapid and Cost Effective Method for Field/Laboratory Extraction of Porewater from Whole Lake Sediment using Vacuum Extraction
Authors: McCauley DJ , Navarro JE , Forgette TA
Published: March 2009

The use of an electric vacuum pump to extract porewater from whole lake sediment was tested to determine if this method could be used to collect a sample quickly and economically for determination of sediment contamination. Multiple aquarium air stones (15 cm long) were placed evenly throughout the sediment sample and attached to a vacuum flask using aquarium tubing. An electric vacuum pump was used to create a vacuum, which pulled sediment porewater from the sample into the flask. In our investigation, sediment porewater was extracted at a rate of 9.7 mL/min with minimal labor investment. Percent similarity of duplicate chemical analyses ranged from 67 to 100% and percent similarity of duplicate acute toxicity results was 96%. Increased variability in both analytical and toxicological results was observed in samples collected in close proximity and this variability increased as sediment toxicity increased. Percent similarity of acute toxicity results using porewater extracted by vacuum and centrifugation methods were 84% for contaminated porewater and 100% for reference porewater.
Use of Behavioral Avoidance Testing in Natural Resource Damage Assessment
Authors: Lipton J , Little EE , Marr JCA , DeLonay AJ
Published: March 2009

Natural Resource Damage Assessment (NRDA) provisions established under federal and state statutes enable natural resource trustees to recover compensation from responsible parties to restore injured natural resources. Behavioral avoidance testing with fish has been used in NRDAs to determine injuries to natural resources and to establish restoration thresholds. In this manuscript we evaluate the use of avoidance testing to NRDA. Specifically, we discuss potential “acceptance criteria” to evaluate the applicability and relevance of avoidance testing. These acceptance criteria include: (1) regulatory relevance, (2) reproducibility of testing, (3) ecological significance, (4) quality assurance/quality control, and (5) relevance to restoration. We discuss each of these criteria with respect to avoidance testing. Overall, we conclude that avoidance testing can be an appropriate, defensible, and desirable aspect of an NRDA.
A Review of Laboratory Toxicity Identification Procedures-Investigative and Applied Approaches
Authors: Hall WS
Published: March 2009

This paper reviews some of the laboratory Toxicity Identification Evaluation (TIE) protocols published to date. A history of the development of these techniques and their application in effluents is presented. Also presented are examples of applications of these techniques, a review of selected techniques, a summary of individual techniques and the chemicals they remove or render nontoxic, and case studies. Many laboratory TIE techniques are available beyond those published by USEPA, and a myriad of techniques have been successfully applied. The published techniques were found to be generally “investigative” or “applied” in nature. It is concluded from this review that the generally chemical-specific investigative techniques and the applied techniques, which do not emphasize the identification of specific toxicants, can both be useful under various conditions. However, it is recommended that as a means to preliminarily evaluate fullscale wastewater treatment options and possibly identify specific toxicants amenable to “upstream” control, laboratory TIE methodologies combining both approaches be used.
The Risk Implications of the Distribution of Chromium Forms in Environmental Media
Authors: Mahoney LA , Petroff DM , Batey JC
Published: March 2009

Chromium exhibits multiple oxidation (valence) states, ranging from (-II) to (+VI). Under natural conditions, however, chromium typically exists in the Cr(III) (trivalent) and/or Cr(VI) (hexavalent) form, with the hexavalent form exhibiting higher solubility and much greater toxicity than the trivalent form. Due to the large differences in toxicity, the distribution of chromium oxidation states (Cr(III) and Cr(VI)) in site media is potentially of great importance to the calculation of site risk levels, and thus ultimately to cleanup activities. Despite its importance, chromium oxidation states are often not available for media samples collected at waste sites.

Typical assumptions regarding the chromium distribution in site media are presented. Actual chromium distribution data from media from baseline investigations of several waste sites are also presented for groundwater, surface water, and soil and compared in terms of background chromium levels and the nature of site wastes. The differences in toxicity of Cr(III) and Cr(VI) are briefly discussed. Risk estimates and risk-based cleanup levels generated using different assumptions for the distribution of chromium in site media for a selected example site are then given. These risk-based cleanup levels are compared to various state regulatory limits, MCLs, and Practical Quantitation Limits (PQLs) for chromium.
A Wavelet-Based Method to Analyze CPT Data for Geotechnical and Geo-Environmental Site Characterization
Authors: Li B-L , Yeung AT
Published: March 2009

The applications of cone penetration technology (CPT) in geotechnical and geo-environmental engineering are increasing due to recent advances in electronics and sensors that can be installed on the cone. However, interpretation of CPT data is a complex process and most existing methods are either empirical or semi-empirical. In order to fully utilize the capability of CPT, issues of local feature identification, uncertainty quantification, and scale effects on the interpretation of collected data have to be addressed properly. In this paper, wavelet transform and wavelet variance are used to characterize the essential scales of CPT data, and wavelet transform modulus maxima and phases are used to detect instantaneous frequency change. The scale effects of site stratigraphy determination using CPT data are demonstrated. The results indicate that this wavelet-based approach can provide a promising tool to reduce uncertainties in CPT data interpretation.
Effects of Food Label Health and Nutrition Claims on Consumer Perceptions
Authors: Corney MJ , Issanchou S , Shepherd R , Griffin K , Nanayakkara C , Daillant B
Published: March 2009

Two experiments are reported that examined consumers' perceptions of food package labels where health and nutrition claims were present and where they had been removed. Unlike previous studies examining the influence of information on perception, realistic materials were used. This was accomplished by presenting information on a computer as photo-realistic images of packages where claims had been removed by editing to give a without-claims condition. Automatic presentation of materials and data collection meant participants proceeded through the computer questionnaire without the presence of an experimenter. The experiment was conducted with both British and French consumers. No significant difference on purchase intention or attitude to purchase was found between conditions with either population sample.

The British group showed a significant trend to rate products as likely to be approved by those whose opinion they regarded as important in the claims condition. French participants showed a similar effect whereby packages without claims were always perceived as significantly beneficial with a low subjective norm effect and a mixture of both factors with claims present. In both population samples, label information provision was evaluated more highly than a collection of single sensory and nutritional attributes. Multiple regressions against attitude to purchase showed that sensory attributes were given higher weighting than nutritional or direct label attitude measures with both groups. Argument that health and nutrition claims are likely to have very large effects on consumers' buying patterns thus may be treated with caution. These results suggest that from a marketing perspective where claims are relevant they should be given a subsidiary position to claims about sensory qualities.
Consumer Use of Package Directions of Varying Formats for Familiar and Unfamiliar Food Products
Authors: Levis PA , Chambers E , Chambers DH , Hollingsworth MG
Published: March 2009

Cooking or handling directions found on a food package are among the many pieces of information conveyed to the consumer through packaging. This study examined consumer use of preparation directions for food products and which of three formats of directions (paragraph, step-by-step, and graphical/text) consumers prefer. The study was conducted in two parts: (1) a quantitative survey of food preparers and (2) product preparation/focus groups. For the product preparation, both a familiar (macaroni) and an unfamiliar (stuffing mix) food product were prepared. Results from the survey indicated that most consumers said that they read directions. However, our focus groups showed that consumers read only directions for the unfamiliar product and then followed what they considered to be essential information. When given a choice, consumers prefer directions that are easy to read and quick to reread, such as a step-by-step or graphical/text format.
Choosing the Best Package: Sensory Scaling Provides Better Guidance
Authors: Gunn C , Cooper H
Published: March 2009

Product packs and packages protect the contents but also contribute significantly to consumer perceptions of the brand and product through color and design. If advertising budgets are low, the pack plays a major sales role at the point-of-sale by communicating its product contents and brand image to consumers.

A theory of consumer interaction with packaging is proposed that consists of four stages: 1. Impact (noticeability at point-of-sale). 2. Imprint (message or image communicated). 3. Ident (communication fit with consumer needs). 4. Intent (sum of the first three in terms of intention to buy).

This theory forms the basis of an integrated approach for assessing packaging—combining qualitative research, perceptual mapping, and sensory scaling techniques. Sensory techniques are used to diagnose specific pack design elements and their contribution to the overall message or image. Direction can be given for optimization of the pack design, even in situations where there is a need to harmonize designs across more than one geographical market.
Dislocation Amplitude-Dependent Damping in Crystals
Authors: Kustov SB , Golyandin SN
Published: March 2009

Experimental investigations of the amplitude-frequency dependences of the dislocation amplitude-dependent damping (ADD), amplitude-dependent Young's modulus defect, and reversible nonlinear anelastic strain in a number of crystals served as a basis for the phenomenological description of the dislocation amplitude-dependent damping and quantitative analysis of its components. A rheological model with a corresponding differential equation has been constructed to describe the amplitude-frequency spectra of the dislocation anelasticity. Calculations according to the proposed model revealed a good correspondence with the experimental data. Some parameters of the model, accounting, for example, for the effective stress component and its dependence on the anelastic strain rate, are found in some cases to be the same for the macro — and reversible microplastic deformation.

It has been shown that there exist at least three contributions, which may form the amplitude-frequency spectra of ADD due to dislocation motion: (i) overcoming of the internai stress “ripples” or internal stress field hysteresis, (ii) thermally activated, and (iii) athermal overcoming of point obstacles. These three components appear to be linked, in general, to the different levels of the defect structure of the crystals: interaction of dislocations, and perhaps, dislocation groups, and interaction of isolated dislocations with point obstacles. Limitations of the proposed phenomenological description are also discussed. Finally a qualitative microscopic description of dislocation nonlinear anelasticity is proposed, based on the “nonlocalized friction” concept.
A Study of the Internal Friction Associated with Discontinuous Precipitation in Lead-Tin Alloys
Authors: Lu J , Van Aken DC , Leighly HP
Published: March 2009

Lead alloys containing up to 20 atomic percent (at%) tin were solution treated and then cooled through the solvus temperature while measuring the internal friction. At the start of the precipitation reaction the damping decreased as a result of β-tin (Sn) particles pinning grain boundaries. An internal friction peak was also observed and was found to be associated with the growth stage of the discontinuous precipitation reaction. Cooling rate and frequency dependence of the internal friction peak were observed to obey the previously proposed models for first-order phase transformations. Internal friction peak height increased as the cooling rate was increased and the frequency dependence indicated an inverse relationship with an exponent of 0.59, that is, f-0.59. The frequency dependence, with a slope greater than - 1, supports the intergranular mode of discontinuous precipitation of β-Sn from α-lead (Pb) under our experimental conditions. The exact nature of the anelastic strain associated with the internal friction peak is yet unclear, but may be associated with a ledge-terrace mechanism for the cooperative growth of the β-Sn and α-Pb lamellae.