bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Stacking Sequence on Damage Propagation and Failure Modes in Composite Laminates
Authors: Ratwani MM , Kan HP
Published: March 2009

The effect of stacking sequence on damage growth and failure modes in composite laminates is discussed. Tests were conducted on AS/3501-6 graphite/epoxy coupons with four different stacking sequences. All laminates had the same percentage of 0, 90, and ±45 degree plies. Constant amplitude fatigue tests were performed at R (minimum to maximum stress ratio) = −1.0 and −∞. The specimens were periodically taken out of the testing machine and subjected to nondestructive inspection using X-ray radiography with diiodobutane.

The results of nondestructive inspection indicate that the direction of damage propagation depends on the stacking sequence in the composite laminate. The damage may propagate predominantly along the loading direction or in a direction at some angle to the loading direction, depending on the stacking sequence. Interlaminar stress analysis of four laminates was performed to correlate the direction of damage propagation with the nature of interlaminar stresses.
Use of Luminescent Bacteria for Determining Toxicity in Aquatic Environments
Authors: Bulich AA
Published: March 2009

A simple rapid method for monitoring the toxicity of aquatic samples has been developed. The assay is based on changes in the light output of luminescent bacteria, as measured in a photometric device. Under suitable conditions, selected strains of luminescent bacteria emit a constant amount of light as a metabolic by-product. On exposure to toxicants, the light intensity is quickly diminished by an amount which is proportional to the concentration of the toxicant. An initial comparison of this new method with a 96-h acute fish toxicity test suggests that the bacterial test compares favorably in sensitivity with other tests while being more simple and rapid to perform. Data can be obtained in two to five minutes. Some examples of demonstrated sensitivities (in mg/litre) are: pentachlorophenol, 0.005; carbon tetrachloride, 6.0; sodium lauryl sulfate, 1.0; chlordane, 0.6; and sodium hypochlorite, 0.005.
Embryo-Larval Toxicity Tests with Organic Compounds
Authors: Birge WJ , Black JA , Hudson JE , Bruser DM
Published: March 2009

A continuous-flow system was developed for evaluating the effects of insoluble and volatile organics on the developmental stages of fish. A closed test system, devoid of standing air space, was used to minimize volatility as a variable. Insoluble compounds were suspended in influent water by mechanical homogenization, without the use of carrier solvents. Tests were performed with aniline, chlorobenzene, and phenol. Water hardness was maintained at 50 and 200 mg/litre calcium carbonate, and exposure was continuous from fertilization through four to eight days after hatching for largemouth bass, channel catfish, goldfish, and rainbow trout. The results indicated that there was good reproducibility of exposure concentrations down to 1 µg/litte or less. For a calculated concentration of 1 µg/litre phenol, the actual test-water concentrations (mean ± standard error) for four replicates were 0.7 ± 0.2, 1.2 ± 0.3, 1.3 ± 0.3, and 1.5 ± 0.3. When phenol was administered in hard water, the LC1 and LC50 values determined at hatching were 0.2 and 80 µg/litre for trout, and 2.0 and 710 µg/litre for goldfish. Phenol was less toxic in soft water. Chlorobenzene at 0.09 mg/litre produced complete mortality of trout eggs. When bass eggs were exposed through four days after hatching, the LC50s for chlorobenzene ranged from 50 to 60 µg/litre. The aniline LC50 values calculated for catfish, goldfish, and bass eggs treated in soft water were 5.6, 10.2, and 47.3 mg/ litre, respectively. Because of the differential rates of larval mortality for the three species, the LC50 range narrowed considerably when the exposure time was increased beyond hatching. Water hardness exerted no appreciable effects on the toxicity of either chlorobenzene or aniline. All three organic compounds produced significant frequencies of teratic larvae.
A Chronic Toxicity Test with the Marine Copepod Acartia tonsa
Authors: Ward TJ , Rider ED , Drozdowski DA
Published: March 2009

A chronic toxicity test was developed for studying the effects of five toxicants (effluents) on the survival and reproduction of Acartia tonsa, a marine zooplankton. The test involves the exposure of copepods to three concentrations of each material (320, 100, and 32 ppm) for an entire life cycle. It is divided into three parts: (1) the reproduction of laboratory-cultured Acartia tonsa in breeding chambers containing the three concentrations of toxicants under static conditions; (2) sexual maturation of the F1 organisms in the toxicant concentrations under flow-through conditions; and (3) the reproduction of the F1 organisms under the same conditions as those established for Part 1, and the monitoring of the organisms' reproductive success, defined as the number of viable F2 offspring.

The results of the chronic tests were compared with data from an acute study conducted earlier. The chronic tests showed a significant reduction in organism survival, when compared with the acute tests (in the range of 1.0 to 0.1 percent of the 48-h LC 50 value). This paper highlights the relative simplicity of the chronic Acartia tonsa test procedure and demonstrates its twofold usefulness: (1) in the identification of a long-term effect and (2) in the comparison of the chronic toxicity of differing materials.
Use of the Grass Shrimp (Palaemonetes pugio) in a Life-Cycle Toxicity Test
Authors: Tyler-Schroeder DB
Published: March 2009

A methodology for using the estuarine grass shrimp (Palaemonetes pugio) in life-cycle toxicity tests was successfully developed.

Life-cycle exposures of juvenile shrimp (12 to 19 mm in rostrum-telson length) to the chlorinated hydrocarbon pesticide endrin were begun in November 1976 and completed in March 1977. After the juveniles matured and spawned, the effects on their progeny were determined. Tests were conducted in a flow-through seawater system, using a modified Mount and Brungs diluter. The average measured exposure concentrations were 0 (control), 0.03, 0.05, 0.11, 0.18, 0.38, and 0.79 µg endrin/litre seawater.

The juveniles reached sexual maturity during the first two weeks of the exposure. Thereafter, a photoperiod regime was used to induce reproduction, and the effects of endrin on the survival, growth, and reproduction of the parent generation were determined. Larvae spawned by control and exposed parents were continuously exposed until the juvenile stage (7 to 20 mm in rostrum-telson length). The effects on survival, length of larval development, and growth of the F1 generation were determined.

The 96-h LC50 for juvenile grass shrimp was 0.35 µg endrin/litre water. In the life-cycle toxicity test, gonadal development and spawning were inhibited at 0.03 µg endrin/litre water. Because this was the lowest concentration tested, the maximum allowable toxicant concentration could not be determined. The specific application factor for grass shrimp is, therefore, less than 0.08, approximately one order of magnitude lower than those generated in life-cycle tests exposing freshwater and estuarine fishes to endrin.
Bioaccumulation of DDT and PCB in Tissues of Marine Fishes
Authors: Butler PA , Schutzmann RL
Published: March 2009

Fishes of commercial importance were monitored in New England coastal waters in 1974 to determine whether synthetic organic residues in the fish were large enough to affect the utilization of such fish as food by man or to interfere with their ability to reproduce. About 700 fish of 20 species were pooled in samples of five to ten, and the livers were analyzed. Several species, including the spiny dogfish, contained residues of dichlorodiphenyltrichloroethane (DDT) and its metabolites and of polychlorinated biphenyl (PCB) compounds in the 1 to 10 μg/g (ppm) range. More detailed studies of the dogfish in 1975 demonstrated the transfer of these compounds from the parent fish to the ovarian egg and the mature fetus.

The proportions of the DDT metabolites found suggest that this pesticide had been accumulating in the 18 to 20-year period of maturation of the female and was passed on to the first brood of young. In contrast to the findings of other investigations, there was no fixed relationship in the relative magnitude of DDT and PCB residues when both compounds were present in a sample.
Test of a Model for Predicting Kepone Accumulation in Selected Estuarine Species
Authors: Bahner LH , Oglesby JL
Published: March 2009

Extensive testing has shown that Kepone is rapidly accumulated by estuarine animals when administered in water or food. Flow-through laboratory experiments with oysters, shrimp, crabs, and fish indicate that the food-chain transfer of Kepone is important in predicting Kepone residues in estuarine organisms. The rates of Kepone movement through estuarine organisms were previously unknown; rates of uptake and depuration by these organisms were determined with a regression model that describes mathematically the uptake and depuration of Kepone by these organisms. The model describes biological data as a single equation, thus allowing variations, due to many physical, chemical, biological, and random-error factors, to be analyzed simultaneously.

The direct application of this model to cautious extrapolation will aid administrative decisions that affect water quality. The rates calculated by this single-species model can be also used in developing models that can predict the long-term fate of Kepone or of other pollutants in an estuarine environment.
Interpretation of Chemical Water Quality Data
Authors: Lee GF , Jones RA
Published: March 2009

Meaningful interpretation of water quality data requires an evaluation of the reliability of the data. Particular attention must be given to evaluation of the applicability of the analytical methods used, sampling and sample handling procedures, and analytical quality control program.

There are many problems with the use of the U.S. Environmental Protection Agency (EPA) water quality criteria as a basis for evaluating water quality. Meaningful interpretation of data requires consideration of the concentration-time of the exposure relationships that exist at a given location within a body of water where the concentration of a chemical is in excess of the U.S. EPA criterion. Also, consideration must be given to the amount of the contaminant which is available to affect water quality. This may require the use of bioassay procedures since, in general, chemical procedures provide a relatively poor estimate of the amount of available contaminant present in a water sample. In addition, consideration must be given to the physical and chemical characteristics of the water since they may markedly affect the significance of a chemical contaminant for water quality.
Ecological Kinetics of Silver in an Alpine Lake Ecosystem
Authors: Freeman RA
Published: March 2009

The cycling characteristics of silver were studied in a small watershed and lake in the Colorado alpine region. The sources of silver for the watershed were atmospheric fallout and washout, groundwater percolation, and cloud seeding. Monthly synoptic samples of snow, stream and lake water, groundwater, soil, sediment, sediment interstitial water, aquatic plants, benthos, seston, and fish were analyzed for two years. The biological samples were subjected to acid digestion while ammonium pyrrolidine dithiocarbamate-methyl isobutyl ketone (APDC-MIBK) extractions were performed on the aqueous samples. Silver in the sediment was extracted by iodide complexation.

1The silver concentrations showed marked seasonal variations in all ecosystem components studied, and this implied a partially reversible mechanism of bioaccumulation. Variations in silver concentration in the ecosystem components were statistically correlated on the basis of their physical and biological interactions, and these correlations provide a framework for an annual silver cycle. A chain of effects initiated by terrestrial climatological events is hypothesized to be causal in the levels of silver which eventually appear in aquatic biota and environments.
Transport and Transformations of Anthracene in Natural Waters
Authors: Southworth GR
Published: March 2009

Polycyclic aromatic hydrocarbons (PAH) commonly occur in wastes from pyrolysis of biogenic fuels. Because some PAH are known carcinogens, an understanding of their environmental behavior and persistence is critical to determining their potential hazard to man. While many processes may remove or transform PAH in aquatic ecosystems, several may be particularly important in determining the fate of PAH in most systems. Laboratory measurement of the rates of various processes under controlled conditions are identifying those critical parameters of environmental transport where more detailed research is necessary.

Anthracene was selected as a representative PAH because of its intermediate molecular weight and its lack of carinogenicity. The rate of photolysis, hydrolysis, volatilization, and microbial degradation of anthracene were measured under different environmental conditions, using fluorimetric and radiotracer techniques. The equilibrium constants for processes such as sorption and bioaccumulation were also determined.

The results of the study indicated that photolysis and microbial degradation within the water column are likely to be the dominant pathways of anthracene removal from aquatic systems. More research is needed to ascertain the degree to which the microbial degradation rates observed in this study are representative of other PAH-contaminated systems. Further study of the role of microbial degradation in bedded sediments in the removal of PAHs from the water column is also necessary.
Rodent Population Activity Monitoring Methods for Evaluating Acute Rodenticide Tracking Powders
Authors: Williams RE
Published: March 2009

The field test protocol required by the U.S. Environmental Protection Agency (EPA) for field efficacy determinations of experimental rodenticides subject to EPA product registration consideration was evaluated. The two population monitoring methods used to fulfill the EPA requirement of a dual system of evaluating pretreatment and posttreatment rodent population levels were nontoxic food consumption and nontoxic tracking dusts. In these field experiments, both monitoring methods used were designed to measure test-population activity levels (that is, the population density) rather than test population size (that is, the numbers of animals), as was required by the EPA protocol. The measure of population activity levels appeared to describe adequately the effects of the rodenticide exposure on the test populations. The required dual system of population monitoring and the required duration of the testing period appeared to be unnecessarily costly. A single population activity monitoring method and a shortened test duration would seem to be adequate for evaluation of the field efficacy of experimental acute rodenticide tracking powders.
A Safe and Inexpensive Way of Making South Korean Villages Rodent-Free
Authors: Howard WE , Park JS , Cho WS , Kim SI
Published: March 2009

The test methods used in this rodent control program, which can be tried by others, are unique in being exceptionally safe to people and to nontarget animals and very saving of bait material, which is important to many countries. Bait stations (boxes) are used. For safety and economic reasons, no poison bait is put in the bait stations until a spoonful (5 g) of whole rice (Step 1) has first been taken from the station by a rodent. Next, if many rats are present, 25 g of a prebait (Step 2) is put in the bait station. When all of the prebait is eaten, an acute rodenticide bait, in our tests 5 g of 0.5 percent RH 787 (Vacor), is added as Step 3. That is followed by Step 4, 25 g of anticoagulant bait. When toxic bait is no longer being eaten (because all the rodents are controlled), a spoonful of rice (Step 1), which deteriorates far less rapidly than ready-made baits and is safer, is put in the station and left until a new rodent appears. This paper also describes precontrol and postcontrol census methods, acceptance tests of bait material and of the toxic bait used, a method for determining the presence of survivors, and tests to distinguish new invaders from individuals that have become shy of the bait or the toxicant or both. Since a successful control program depends on an effective organizational structure, a Korean example is given to show how complex such a structure can be.
Age as a Factor in Rodent Susceptibility to Rodenticides—A Review
Authors: Salmon TP , Marsh RE
Published: March 2009

Age is discussed as a factor in the susceptibility of animals to iodenticides such as strychnine, ANTU, anticoagulants, arsenic, crimidine, endrin, barium carbonate, and chemosterilants. Age-differential mortality will be of importance if the difference is great enough and if baits cannot be strengthened without the loss of bait acceptance. Some possible implications of these age-related differences to actual rodent control practices and to laboratory and field efficacy tests are discussed. Agerelated toxicity differences of some rodenticides to certain nontarget species are included for practical and comparative purposes. Age-specific toxicity tests are suggested. The authors speculate that age-related behavioral traits may play an independent role or compound an age-toxicity association.
Microtus Dry Bait Laboratory Efficacy Test Method
Authors: Byers RE , Palmateer SD
Published: March 2009

This laboratory test was designed to determine the effectiveness of toxic baits used against pine and meadow voles. The test is adaptable for both single-feeding and multiple-feeding rodenticides. A new challenge diet for voles has also been developed, and the rationale for its use is discussed. A vole toxicant tested with this method is considered satisfactory if a 90 percent vole mortality is achieved.
Evaluation of Deer Damage in Mature Apple Orchards
Authors: Katsma DE , Rusch DH
Published: March 2009

The impact of winter deer (Odocoileus virginianus) browsing on apple production was studied in three commercial orchards in southwestern Wisconsin. Estimates of the proportion of apple buds available to deer, the percentage of available buds browsed, and the apple production were obtained for about 500 sample trees in 1975 and 1976. The accuracy and precision of estimation procedures were evaluated, and the relationship between browsing and production was analyzed. The availability of apple buds to browsing deer was primarily a function of the size and shape of the apple trees. Visual and photographic appraisal indicated that ellipsoids best described the shapes of apple tree crowns, so the proportion of buds available was calculated from equations for ellipsoid volumes for each tree. Good estimates of proportions of available buds browsed were obtained from bud and nip counts on a 2.5 percent sample of the trees, and subjective estimates of the proportion of available buds browsed were correlated with proportions calculated from the actual counts. Multiple regression analyses suggested that the degree of browsing was related to the cultivar, size, and location of the apple trees. In the orchards studied, 34 and 10 percent of the growing points were removed by deer in 1975 and 1976, respectively. Analyses indicated that deer browsing decreased apple production on size-controlled (dwarf and semidwarf) trees, but not on standard sized trees. Two methods of evaluating deer damage are proposed. The first method uses realized production figures and estimates of the percentage of the orchard browsed, whereas the second method requires only an estimate of buds browsed in the damaged areas to predict production loss.
Indicator Bird Species for Toxicity Determinations: Is the Technique Usable in Test Method Development?
Authors: Schafer EW , Brunton RB
Published: March 2009

Pesticide, food, drug, and cosmetic industries have used indicator animal species for many years to provide data on the relative hazards of synthetic or natural chemical products to applicators or users. A considerable amount of toxicological information is available on the relative susceptibility of different mammal species to various chemicals. This information has been used to predict hazards to other mammals, including man. Indicator species often are used for evaluating the efficacy of chemicals or their hazards to wild birds. However, the available toxicological information is generally not sufficient to extrapolate valid relationships between the indicator species and the target species.

In this paper we have presented the state of the art for the use of indicator bird species and have expressed our opinion on the use of these data. Because many current uses for bird indicator species are not well supported by available data, we recommend that further test method development with avian indicator species be terminated until additional data can be gathered on the relevancy of the technique.
Evaluation and Results of a Survey of Blackbird and Mammal Damage to Mature Field Corn Over a Large (Three-State) Area
Authors: Stickley AR , Otis DL , Palmer DT
Published: March 2009

Details are presented of a three-stage cluster sampling design used by the U.S. Fish and Wildlife Service to produce estimates of bird and mammal damage to ripening field corn in Ohio, Kentucky, and Tennessee in 1977. Results of the survey are briefly discussed. Analyses were performed that allowed the design to be evaluated and improved for future use. Edge-effect bias, which occurs when damage in the periphery of fields is much greater than damage in the interior, is analyzed and discussed.
Evaluating Curb as a Crop Repellent to West African Bird Pests
Authors: Bruggers RL
Published: March 2009

Techniques for evaluating the efficacy of chemical repellents applied to crops against depredating birds are presented. Curb (aluminum ammonium sulfate) has shown promise as a repellent against several species of granivorous birds when applied to ripening cereals in West Africa. In all the trials, one treatment of 8 to 16 kg/ha protected the ripening grain of rice, millet, and sorghum for between one and two weeks, and, under particular conditions, two treatments gave protection throughout the maturational period.
Laboratory Trials Using Fluorescent Dyes and Paints as Marking Agents for Quelea Studies
Authors: Bruggers RL , Bortoli L
Published: March 2009

Under laboratory conditions 88 percent of Quelea quelea and 100 percent of Ploceus melanocephalus retained a suspension of fluorescent dye in a mixture of castor oil and dieseline for 42 days. Dye still was present on the ventral surfaces of the primaries 115 days after the treatments. Aerial or perhaps terrestrial applications of this dye to nesting quelea may be useful in studying the movements and nesting behavior of this species in those regions of its range where double nestings are suspected. The results of several marking trials for individual recognition under laboratory conditions showed painted leg bands and breast feathers to be the most satisfactory markings for study purposes.
Testing the Responses of Coyotes and Other Predators to Odor Attractants
Authors: Turkowski FJ , Popelka ML , Green BB , Bullard RW
Published: March 2009

A standardized evaluation method was developed and used to compare statistically the efficacy and selectivity of predatory animal lures. A modified scentstation technique included one or more lines with 100 or more stations each, which were placed along unpaved roads in four states.

The exposure of 47 255 perforated plastic capsules containing candidate attractants during a 28-month period yielded 8091 coyote visits and 9474 behavioral responses. Data were obtained on nine additional carnivore species and eleven other animal taxa. Analyses of coyote data indicated significant differences in visit rates and behavioral responses in several categories, including biting and pulling up the lure capsules. Comparisons of mean coyote visit rates for all test lures indicated that DRC-6500, a concentrated synthetic equivalent of a fermented egg synthesized by Denver Center personnel, was the best attractant in nearly all tests. The scent-station technique appears to be reliable for evaluating the relative attractiveness of lures. Comparisons of candidate samples to a base attractant and the resulting indexes will allow animal damage control personnel and researchers to field test the efficacy of candidate lures.
Evaluation of Oral Central Nervous System Depressants in Coyotes
Authors: Savarie PJ , Roberts JD
Published: March 2009

Standardized gross behavioral observation test methods for evaluating the oral effectiveness of central nervous system (CNS) depressants in captive coyotes (Canis latrans) are described. The primary objective of this research was to develop a chemical for use in trap tabs that would reduce escape, struggling, and injuries to animals, particularly carnivores, captured in steel-jawed traps. The classes of chemicals that demonstrated potential for this purpose are the phenothiazines and the benzodiazepines. Of four phenothiazines evaluated, propiopromazine hydrochloride (HCl) and triflupromazine HCl showed desirable properties. Their onset of action was about 10 min, and the duration of major CNS depression lasted for about 24 h. Chlordiazepoxide HCl, a benzodiazepine, showed an onset of action in 30 to 40 min and a duration of 30 to 36 h. Testing these drugs in combination potentiated CNS depression. Propiopromazine and reserpine together produced symptoms of CNS depression that lasted for as long as 72 to 96 h. Potentiation was also noted with propiopromazine and chlordiazepoxide in combination with each other.
Proposed Efficacy Test for Dog Repellents Designed to Reduce Urination on Established Scent Posts
Authors: McCann JA , Snider CC
Published: March 2009

This test provides efficacy data on dog repellents designed to reduce urination on objects, such as tree trunks, bushes, trash cans, furniture, and fire hydrants. Pesticide companies and the U.S. Environmental Protection Agency can use this test to establish or to monitor product efficacy.

At least eight male dogs are exposed in pairs in rectangular enclosed areas until they have urinated at least 300 times (during the reference and repellent test periods together) on any or all of eight artificial scent posts in the enclosed area. The 150 strikes during the reference period establish the urination pattern of the dogs. The 150 strikes during the repellent test period, when four of the scent posts have been treated with a repellent, establish any change in the urination pattern caused by the repellent.

The eight scent posts in the areas are divided into two squares of four. The location of one treated post in each square is determined randomly. The location of the other treated post in the square of four is then automatically determined, as there should be no more than one treated post on any one side of the square.

For comparison purposes, the use of a standard scent post, consisting of two cylinders (a simulated fire hydrant) is recommended. A pipe attached to the outside of the outer cylinder and forced into the ground keeps both cylinders upright. The outer cylinder supports and protects the inner cylinder.

The inner cylinder is made from a lighter weight hardware cloth. This cylinder is covered with filter paper and placed inside the outer cylinder. A dog urinating on the post leaves a stain on the filter that can be easily seen and counted by using an ultraviolet (“black”) light. A repellency value is calculated using the formula: repellency = (1.00 - 2 × St/T) (100), where St equals the observed number of strikes on treated posts, and T equals the total number of strikes observed or expected in the repellent test.

For a dog repellent to be considered effective, it should reduce urination on treated posts by at least 60 percent.
Rationale for Testing Vertebrate Pesticides and Devices in Actual Field Situations
Authors: Beck JR , Stein HS
Published: March 2009

Several problems have been observed and documented over the past 25 years regarding the extrapolation of laboratory and limited field test data directly to vertebrate pest control under actual field situations. Under the new legal and technical complications necessitated by interpretations of the Federal Insecticide, Fungicide, and Rodenticide Act and by environmental and consumer interests, the occurrence of these problems is no longer acceptable to the user. Reasons for these past failures or limitations are discussed candidly. Corrective and preventive procedures are outlined.
Using Computers in Evaluating Vertebrate Pest Control Procedures
Authors: Giles RH
Published: March 2009

Computer use in vertebrate pest management has been suggested for allocating research funds and justifying budgets, and a technique for doing so is suggested. An algorithm for deciding when to use computers is given. Injury and damage are defined, and the role of the computer in determining the marginal difference is supported. Eight specific applications for computers are recommended, including increased use of nonparametric statistical techniques. The use of the computer as a deductive aid in data analysis for managerial decision making is suggested. A regional or national computer program is described both as a means for improving vertebrate pest damage control decisions and as a concept essential for improved evaluation of control procedures.
Fire Response of Organic Polymeric Materials (Organic Materials in Fire: Combustibility)
Authors: Hilado CJ , Murphy RM
Published: March 2009

Organic polymeric materials exhibit a wide range of fire performance when evaluated separately. However, the performance of combinations of materials cannot always be predicted from the performance of individual materials tested separately.

The physical and thermal response characteristics of many materials, and of many combinations of materials, have a greater effect on their fire response characteristics than their chemical composition. For many generic materials, chemical composition changes may have reached the point of diminishing returns because combustibility cannot be reduced further without seriously affecting desirable performance characteristics.

Attention to the design and engineering aspects of materials may be the most cost-effective and in some cases the only means of ensuring their safe use.
Semiautomated Headspace Analysis of Drinking Waters and Industrial Waters for Purgeable Volatile Organic Compounds
Authors: Bellar TA , Lichtenberg JJ
Published: March 2009

The design and operation of a semiautomated dynamic headspace technique for the determination of purgeable volatile organics ate described. All critical analytical functions except the sample introduction step have been automated and are operated under computer control. These include the functions of: purging and sorption, desorption and injection, gas chromatographic analysis and data reduction, and recycling of the purging device and sorbent trap for succeeding analyses.

Application of the system to the analysis of drinking waters and industrial waste waters is discussed. Single-laboratory accuracy and precision data and the results of an interlaboratory study on selected halogenated purgeable compounds are presented. The method has been applied to 32 such compounds that are considered by the U.S. Environmental Protection Agency to be hazardous or toxic materials. These include the haloforms; other chlorinated compounds ranging from gases (at room temperature), such as vinyl chloride, to liquids, such as dichlorobenzenes; and nonhalogenated compounds, such as benzene and toluene.

Sample collection, shipment, and storage procedures are recommended. Optimized analytical operating conditions are defined for the sample size, the purge time and flow rate, the trap dimensions and sorbent materials, the desorption temperature, time and flow rate, and the gas chromatographic conditions. Flame ionization and halogen-specific (conductivity or microcoulometric titration) detectors are used for qualitative and quantitative determination.
Application of Deuterated Organics as Internal Standards in Volatile Organic Analysis from Drinking Water and Wastewater by Computerized Gas Chromatography—Mass Spectrometry
Authors: Nowicki HG , Devine RF , Kieda CA
Published: March 2009

A method utilizing computerized gas chromatography-mass spectrometry (GC-MS) is presented for qualitative and quantitative determination of volatile organics in drinking waters, natural waters, or industrial effluent waters. It is based on the addition of deuterated internal standard, 1,2-dichlorethane-d4, to an appropriate-sized portion of sample and use of the Bellar-Lichtenberg method of purge-trap-desorb into determinative instrument. Method validation consisted of analyzing volatile priority pollutants at 2, 10, 50, 100, and 200 ppb with internal standard at 20 ppb in each of seven replicate analysis at each dose. Comparison of relative standard deviations (RSD) of internal and external standard methods of GC-MS analysis revealed no significant differences. This study also yielded valuable information concerning repeatability, reproducibility, stability of internal standard, linear dynamic range of GC-MS, and RSD variation with different area regenerations of diagnostic atomic mass units. Pollutant identification is based on retention time and total mass spectral comparison with authentic compound. Quantitation is based on measurement of the areas of retrieved diagnostic atomic mass unit regeneration of contaminant and internal standard. Using response factors determined from analysis of standard mixtures containing compounds of interest and internal standard, and the known mass of internal standard, the concentration is calculated. Lower detection limit for the volatile priority pollutants is approximately 1 μg/litre. This method has detected several volatiles that are not Environmental Protection Agency priority pollutants.
Determination of Polynuclear Aromatic Hydrocarbons in Refinery Water Streams
Authors: Preston HG , Macaluso A
Published: March 2009

A procedure has been developed for the analysis of polynuclear aromatic (PAH) hydrocarbons in water samples at levels of 1 μg/litre (parts per billion). The method has been successfully applied to field samples and consists of (1) extracting a neutral fraction from water using methylene chloride, (2) concentrating the extract in a Kuderna-Danish evaporative concentrator, (3) isolation of a PAH fraction by thin-layer chromatography, and (4) quantitative analysis of individual compounds by HPLC. A variable-wavelength ultraviolet detector is used simultaneously with a fixed-wavelength (254 nm) detector to positively identify each PAH by means of peak height ratios at the different wavelengths. An alternate method for isolating and concentrating PAH from water samples was also evaluated. A large volume of water was passed through a column packed with a reverse phase packing, C18-bonded silica, and the organic components were eluted using an organic solvent. This fraction was then analyzed as before. The overall effectiveness of the method has been evaluated using spiked samples containing several standard PAH and the use of an internal standard, such as 14C-labeled benzo[a] pyrene or perylene, has been investigated.
Survey Analysis of Phenolic Compounds in Industrial Effluents by Gas Chromatography—Mass Spectrometry
Authors: Shackelford WM , Webb RG
Published: March 2009

Analyzing industrial effluents for phenolic compounds involves a number of problems both in the separation of these compounds from the aqueous medium and in the chromatography of the extracted compounds. Use of a continuous liquid-liquid extractor improved the recovery of phenolic compounds from those effluents that formed intractable emulsions during liquid-liquid extraction by shake-out. Tenax GC and SP-124O DA proved to be the best general-purpose gas chromatographic column packings for a broad range of phenolic compounds. Derivatization procedures using diazomethane and pentafluorobenzyl bromide were found to be successful only under rigorously controlled conditions. For survey work, it appears that derivatization is of questionable value for initial qualitative analysis, because is many cases, the character of the matrix is not known.
Analysis of Phenols in Some Industrial Wastewaters
Authors: Mousa JJ , Whitlock SA
Published: March 2009

A protocol developed by the U.S. Environmental Protection Agency for the screening analysis of phenols in industrial wastewaters is evaluated and compared to several alternative methods for extraction of phenols from industrial wastes. Raw creosote and pentachlorophenol wood preserving wastes are used as test samples. An alternative liquid—liquid extraction technique, a steam distillation technique, the use of a continuous liquid—liquid extractor, and an ion exchange technique are evaluated. All the techniques appeared to yield similar results. The protocol procedure is preferred for its simplicity but may not be the method of choice, depending upon the nature of the sample matrix.
Interlaboratory Comparison of Environmental Analyses Associated with Increased Energy Production
Authors: Hertz HS , Hilpert LR , May WE , Wise SA , Brown JM , Chester SN , Guenther FR
Published: March 2009

In order to begin evaluating the state of the art of the determination of pollutants associated with the production of alternate fuels (for example, liquefied coal and shale oil), five collaborative studies have been conducted by the National Bureau of Standards. The aim of these initial studies was to ascertain how well participating laboratories could perform the chromatographic quantitation that is often the final step in a trace organic analytical scheme for priority pollutants. The materials examined in the collaborative studies were polynuclear aromatic hydrocarbons in hexane, phenols in water, phenols in hexane, and N-heterocyclic compounds in hexane. Each of these materials contained between five and eight pure compounds, each compound present at the 1 to 100 μg/ml (ppm) level.
Approaches to Comprehensive Analyses of Persistent Halogenated Environmental Contaminants
Authors: Stalling DL , Smith LM , Petty JD
Published: March 2009

A series of chromatographic processes has been integrated into an automated sequential procedure that has been specifically developed for uninterrupted purification and fractionation of multiclass organic chemical residues from environmental samples. The effectiveness and general applicability of this sequential cleanup and fractionation procedure were demonstrated by the recovery of 39 chemicals representing a broad range of residue classes from a fortified fish sample. A chromatographic controller under construction is designed to carry out the numerous sample and solvent manipulations in an automated and continuous procedure. Alkali metal hydroxide treated silica gel effectively separated phenols and acids from neutral compounds.
Preliminary Investigation of a Novel Combined Capillary Column Gas Chromatography-Mass Spectrometry Technique for the Characterization of Fuel Spills in Natural Waters
Authors: Velde GV , Stork JR , Skinner RF
Published: March 2009

The analysis of spilled fuels in natural waters by combined gas chromatography-mass spectrometiy is shown. Analyses are done with the use of wall coated glass capillary columns. A new type comparison technique for fuels is employed that utilizes mass chromatographic profiling techniques to typify the fuels. Preliminary results indicate the technique to be a good technique for spill characterization and to be relatively free of sample weathering and aging problems, if the proper compound classes are chosen. The results of this study are preliminary in nature.
NASA-Langley Research Center's Participation in a Round-Robin Comparison Between Some Current Crack-Propagation Prediction Methods
Authors: Hudson CM , Lewis PE
Published: March 2009

A round-robin study was conducted which evaluated and compared different methods currently in practice for predicting crack growth in surface-cracked specimens. This report describes the prediction methods used by the Fracture Mechanics Engineering Section, at NASA-Langley Research Center, and presents a comparison between predicted crack growth and crack growth observed in laboratory experiments.

For tests at higher stress levels, the correlation between predicted and experimentally determined crack growth was generally quite good. For tests at lower stress levels, the predicted number of cycles to reach a given crack length was consistently higher than the experimentally determined number of cycles. This consistent overestimation of the number of cycles could have resulted from a lack of definition of crack-growth data at low values of the stress intensity range.

Generally, the predicted critical flaw sizes were smaller than the experimentally determined critical flaw sizes. This underestimation probably resulted from using plane-strain fracture toughness values to predict failure rather than the more appropriate values based on maximum load.
Assessment of the Sensitivity of Crack Growth Rate Constants to Predictive Accuracy of Part-Through Crack Fatigue Life Predictions
Authors: Chang JB
Published: March 2009

Fatigue crack life predictions were performed for specimens containing part-through cracks subjected to constant-amplitude loading. A computer routine, EFFGRO, was employed in the crack growth predictions. Three rounds of predictions were made by using different crack growth rate constants derived from the compact- type (CT) specimen da/dN versus ΔK data. The predictive accuracies of each round of predictions were assessed. The results show that accurate predictions of part-through crack fatigue lives using CT specimen crack growth rate data can be achieved if there are known part-through crack test data serving as guidelines.
Surface Crack K-Estimates and Fatigue Life Calculations in Cannon Tubes
Authors: Underwood JH , Throop JF
Published: March 2009

K solutions for internal surface cracks in pressurized cylinders are compared, including Smith's photoelastic results, Hussain's collocation and compliance results, and Underwood's estimates. Fatigue crack growth observations from cannon tubes are described, particularly in relation to surface crack growth and multiple cracks.

A method is proposed for describing quantitatively the effect of residual stress on K in cylinders with shallow cracks. The combination of compressive residual stress with applied stress reduces ΔK and thus increases fatigue life.
Environmental Regulations-United States and California
Authors: Bert JA
Published: March 2009

According to Federal and California environmental regulations, no control of vapor emissions from storage tanks is required if the true vapor pressure of the product is below 10.3 kPa (1.5 psia). Data analysis shows that even for a 15.5°C (60°F) flash point fuel, the true vapor pressure will not reach 10.3 kPa (1.5 psia) until the fuel reaches a temperature of 60°C (140°F) or higher. Flash point reduction of jet fuels to 32°C (90°F) or 27°C (80°F) therefore would not require changes in storage facilities or handling to meet Federal or California vapor emission requirements. The Occupational Safety and Health Administration regulations on benzene concentrations would not be impacted even if flash point were reduced to 27°C (80°F).
Jet A-2, A Fuel to Meet Canada's Energy Constraints
Authors: Salter DE
Published: March 2009

The factors leading to Jet A-2, a new National Standard of Canada [Standard for Turbine Fuel, Aviation: Kerosine Type (CAN2-3.23-77)] of 33°C (92°F) flash point are discussed. Refineries in Canada are limited to a minimum production ratio of gasoline to distillate of about 1.0. Recent trends show a reduced growth rate for gasoline and healthy growth for distillates including jet fuel. Kerosine jet fuel has the most restrictive requirements and the most economical way to increase production is to expand the distillation range. The high demand for low pour point fuel oils for Canada's severe winter climate aggravates the production problem.

A study of major Canadian airports shows Toronto to have the warmest summer temperatures. Average daily maximum ambient temperature from 30-year data is 27°C (80°F), well below the Jet A-2 flash point of 33°C (92°F). This 6°C difference is conservative compared with ambient airport temperatures versus a 38°C (100°F) flash point experienced in other parts of the world. Jet A-2 has a vapor pressure at 38°C (100°F) only slightly greater than Jet A-1 1.0 versus 0.76 kPa (0.145 versus 0.110 psia, respectively). Mixing Jet A-2 with Jet A or Jet A-1 in an aircraft tank will have a minor effect on resulting flash point. The hazard in fuel spills is the possibility of vapors being ignited. Canadian experience with Jet B shows this hazard to be minimal. Data on rate of flame spread over pools of burning fuel show that Jet A-2 represents a small change compared with Jet A.
Some Examples of Acoustic Emission Monitoring of Pressurized Components
Authors: Kelly MP , Pollock AA
Published: March 2009

Four examples of acoustic emission (AE) field tests are described. In the first, standard AE source location techniques were applied to the detection of defects in insulated ethylene piping made of aluminum. Several defects were located and verified through visual and dye penetrant inspections. In the second test, approximately 7000 heat exchanger tubes were monitored for AE response during the manufacturers proof test. Monitoring with AE typically resulted in a one percent rejection rate including a few “leakers” which probably would not have been detected without AE. The initial inservice reliability of heat exchangers with tubes qualified by AE was much greater than for typical heat exchangers not monitored by AE. The third example relates results from a 50 m tall petrochemical tower, demonstrating the ability of AE to locate defects even in the presence of flow noise, tray noise, etc. In the fourth example, an explosive containment cell was monitored during hydrostatic proof test both before and after explosive experiments were carried out inside the vessel. Internal damage to the parent metal as a result of the experiments was easily detectable during the second proof test.
Experience with the Acoustic Emission Monitoring of a Steam Drum Nozzle in a CANdu Nuclear Generating Station
Authors: Baron JA
Published: March 2009

The acoustic emission (AE) monitoring of a steam drum-boiler interface in a CANdu nuclear generating station is described. The component was monitored during both the initial hydrostatic test and a load rejection test. Results obtained were not in complete agreement with those previously presented in the literature. Examination of the three-detection method of source location reveals part of the cause of this discrepancy. Other potential mechanisms for the generation of non-locatable AE events are discussed.
Role of American Nuclear Insurers in Reducing Occupational Radiation Exposure
Authors: Forbes JL
Published: March 2009

Since 1957 the nuclear insurance pools have provided liability and property insurance for the nation's nuclear power generating stations as mandated by the Price-Anderson Act. Although the insurance was originally structured to give financial protection to the insured in the event of a major accident, the potential for third-party claims arising from routine occupational exposure is becoming a more realistic pathway for a loss to the pools. In order to give maximum protection to the pools' assets, the Liability Engineering Department of American Nuclear Insurers (ANI) performs periodic inspections of the power plants. By concentrating on programs and management areas, ANI inspections complement regulatory inspections so that all major areas of common interest are reviewed. This paper presents the nature, results, and findings of those periodic inspections particularly in the general area of plant radiation protection.